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lbodnar
Jan 5, 2004, 11:45 AM
Hello all!

I have just recently got around putting up details of eMac 800MHz upgrade to 1.33GHz/1GB/160GB/OSX10.3

http://www.lbodnar.dsl.pipex.com/eMac/eMac-upgrade.html

As I said there 1.33GHz was not a definite limit but a point when I simply got bored resoldering jumpers. And it IS enough for me!

Do you think this was just a lucky sample or Apple now has to underclock modern efficient CPUs to satisfy low-end Macs production? I guess (as in any manufacturing process) quality of chips constantly and gradually improves and Motorola would not produce "sluggish" chips for a purpose. Having the same line making all the 750MHz - 2GHz range is too expensive logistically?.. Well, that's just my thought.

Could you suggest some application that would push all system to the limit and show how stable it really is? I know from experience that compiling a kernel under Linux is very unforgiving for any CPU-RAM faults but I don't want to install Linux on eMac just for that.

Best wishes!



krimson
Jan 5, 2004, 01:15 PM
try running dnet at a high (7 or 8 should work) setting (i suppose F@H/SETI would work too) then try running Photoshop on a large image, while running DVD2one compressing a 7Gb DVD folder to 2GB.

and while your at it, heat up the room to whatever temp is normal for your summer. For me, that's about 90* F. :D

Jetson
Jan 5, 2004, 01:24 PM
This is an excellent article, lbodnar. My hat is off to one brave soul!

I'd love to bump up my eMac from 1gHz to 1.33gHz. It looks a little hazardous though.

QCassidy352
Jan 5, 2004, 01:40 PM
lbodnar,

xbench 147.81 on an emac! Well done indeed! A very good article, and some nice upgrades to give yourself quite a nice machine! hats off!

Dont Hurt Me
Jan 5, 2004, 02:51 PM
very nice, just goes to show how Apple is Dumbing down the Emac so it dont compete with imac or the old G4 powermac. I wonder how a mod like this will effect its lifespan and i would have liked to see what kind of heatsink was being used. Very Bold step taken by the Author but i dont blame him a bit since Apple doesnt seem to want to build a decent speed Emac or Imac for that matter. way to go ibodnar, why dont you send a copy of this to Apple and tell them you had to take matters into your own hands since they are dicking the dog.
Edit- there is nothing like a topnotch game to stress your system, i would try UT2003 or Halo and then play with your horizontal resolutions, if you can play Ut2003 for a couple of hours with no panics then you should be good to go.

lbodnar
Jan 6, 2004, 07:47 AM
As suggested I have run simultaneously for few hours
- DNET data crunching client at priority 8
- Photoshop 7 applying filters to 1GB image
- saving 40GB folder from LAN server to external Firewire drive
(I don't have DVD videos around to run MPEG compressor)

today I am running UT2003 at minimum and maximum resolutions with no problems.

to Donthurtme:
the heatsink as it is originally is actually a thermal pad with attached heat transfer tube that goes all the way back to where exhaust fan is and there that tube crossects a heatsink which is a set of about 30 very thin "leaves" that seat right in the exhaust airflow. I'll post a picture next time I take it apart.

yamabushi
Jan 6, 2004, 08:30 AM
Good job! This is a great mod. I also think that the G4 in the revised eMac may be an underclocked cpu. That could mean that the iBook is also underclocked.

I think that this might mean that we will see a jump to a 1.33GHz eMac as soon as a G5 iMac is released.

manitoubalck
Jan 6, 2004, 04:41 PM
Originally posted by Dont Hurt Me
Edit- there is nothing like a topnotch game to stress your system, i would try UT2003 or Halo and then play with your horizontal resolutions, if you can play Ut2003 for a couple of hours with no panics then you should be good to go.

Nothing chew's preformace like first person shotter games. Try some with crappy ports and see how it holds up.

By the way I haven't bothered to read the article, but if that's only using the stock passive heat sink then I recomend seeing what can be done with active cooling or better yet a liquid cooling soliution.

manitoubalck
Jan 6, 2004, 04:46 PM
Ok I've read the articl now.

Well done using the stocko HS.
Now the next step is to see how far you can push the FSB. Even my 3 year old AMD K7 runs a faster FSB (200MHz) than your eMac.

Good luck and well done.:D :D

hvfsl
Jan 6, 2004, 05:20 PM
Thats a lot easier than overclocking the PB G4 550 to 667. I wish I had found an eMac that cheaply, I should probably go to PCWorld more often and check out their sales.

lbodnar
Jan 7, 2004, 04:08 AM
Yesterday I have installed Yellow Dog Linux (http://www.yellowdoglinux.com/) on that eMac and compiled Linux kernel about 5 times without a hitch. KDE graphics interface seems so jerky compared to smooth OS X...

virividox
Jan 7, 2004, 04:57 AM
impressive

lbodnar
Jan 10, 2004, 02:10 PM
This sweet little eMac now runs dual-screen. It hasn't failed once during all that time.
http://www.lbodnar.dsl.pipex.com/eMac/eMac-dual-screen.jpg

topicolo
Jan 10, 2004, 04:11 PM
Instead of soldering, can you not use the "pencil trick"?

Crosssing the bridges using graphite and then putting some protective tape over it should allow enough current to pass through the two points to form a circuit, no?

neoelectronaut
Jan 10, 2004, 04:13 PM
Originally posted by lbodnar
This sweet little eMac now runs dual-screen. It hasn't failed once during all that time.
http://www.lbodnar.dsl.pipex.com/eMac/eMac-dual-screen.jpg

How the hell did you pull that one off?

lbodnar
Jan 10, 2004, 05:46 PM
Originally posted by neoelectronaut
How the hell did you pull that one off?

http://www.rutemoeller.com/mp/ibook/ibook_e.html

Re solder pen. This could be an idea but how to remove it if CPU would not pull it up?

neoelectronaut
Jan 10, 2004, 06:18 PM
Originally posted by lbodnar
http://www.rutemoeller.com/mp/ibook/ibook_e.html

Re solder pen. This could be an idea but how to remove it if CPU would not pull it up?

Man...I thumbed through it a little pit (per say) and wow....I don't think I'm willing to do any possible system-damaging things for at least 3 years.

Mord
Jan 11, 2004, 05:49 AM
Originally posted by hvfsl
Thats a lot easier than overclocking the PB G4 550 to 667. I wish I had found an eMac that cheaply, I should probably go to PCWorld more often and check out their sales.

go to john lewis in oxford street they had quite a few emacs for around that price last time i checked

bigbadmac
Jan 12, 2004, 05:19 AM
Great stuff on the 800Mhz. Any input on the 700? I'm only interested in boosting to the min requirement for the new iLife... 733Mhz.

lbodnar
Jan 13, 2004, 08:44 AM
Originally posted by bigbadmac
Great stuff on the 800Mhz. Any input on the 700? I'm only interested in boosting to the min requirement for the new iLife... 733Mhz.

bigbadmac, what processor type Xbench reports on your eMac?

bigbadmac
Jan 13, 2004, 02:24 PM
Processor = PowerPC G4 @700 MHz
Version = 7450 (V'ger) v2.1
L1 Cache = 32K (instruction), 32k (data)
L2 Cache = 256k @ 700 MHz
Bus Frequency = 100 MHz

lbodnar
Jan 13, 2004, 05:14 PM
7450 is different from 7455 and I don't know how good are they for overclocking. Someone has to try! :)

Dont Hurt Me
Jan 13, 2004, 05:23 PM
i dont think you would have a problem i had clocked my 733 (7450) to 800. this is almost certainly the same chip though i was on a 133 bus.

bigbadmac
Jan 13, 2004, 07:27 PM
I'll give it a try if I can get some info on the jumper locations on the MB. Maybe the jumper settings on the 733 are the same? What the heck... my warantee is dead anyway and I've already had to resolder the CRT cable myself...

lbodnar
Jan 13, 2004, 07:42 PM
Originally posted by bigbadmac
I'll give it a try if I can get some info on the jumper locations on the MB. Maybe the jumper settings on the 733 are the same? What the heck... my warantee is dead anyway and I've already had to resolder the CRT cable myself...

way to go, bigbadmac! You can get configuration details from 7455 datasheet (http://e-www.motorola.com/files/32bit/doc/data_sheet/MPC7455EC.pdf). Look for 100MHz bus on page 47. Your options are:
700 ++-++
750 +++-+
800 --+++
850 +--++
etc...
"+" is shorted (0) and "-" is open (1).

Let us know! Can you take a picture of the board to compare with 800MHz eMac?

Dont Hurt Me
Jan 13, 2004, 07:49 PM
Originally posted by bigbadmac
I'll give it a try if I can get some info on the jumper locations on the MB. Maybe the jumper settings on the 733 are the same? What the heck... my warantee is dead anyway and I've already had to resolder the CRT cable myself... i have a different bus 133 so my multiples jumped by 67 mhz different then your bus of 100. i would imagine the same jumpers as the 800 since nothing changed except the chip they inserted. also the 7450 wont be as kind to increasing the speed as ibodnars 7455. i would try to get it to 800 and be happy with that. ibodnar has a nice page at xl8yourmac and the jumpers should be the same. i would talk to him for more info on emac. good luck and dont forget static precautions.

soonbaek
Jan 13, 2004, 08:11 PM
I, too, have original 700Mhz eMac that would love to oc. I've already added 120GB 7200RPM 8MB HD and SuperDriver (re-badged Pioneer A05) but have always wanted more VROOM.

Anyone else with experience oc 7450?

Good job OP! You've given me new hope!

soonbaek
Jan 13, 2004, 08:25 PM
Originally posted by lbodnar
way to go, bigbadmac! You can get configuration details from 7455 datasheet (http://e-www.motorola.com/files/32bit/doc/data_sheet/MPC7455EC.pdf). Look for 100MHz bus on page 47. Your options are:
700 ++-++
750 +++-+
800 --+++
850 +--++
etc...
"+" is shorted (0) and "-" is open (1).

Let us know! Can you take a picture of the board to compare with 800MHz eMac?

[EDIT] D'oh! Spoke too soon. Didnt' see page 37.
I wonder if 7450's limitation is at 800Mhz (8x multiplier). Look at following
7450 datasheet (http://e-www.motorola.com/files/32bit/doc/data_sheet/MPC7450EC.pdf) page 36.

Now it would be really cool to oc FSB from 100Mhz -> 133Mhz!

Rod Rod
Jan 13, 2004, 09:18 PM
amazing!

I installed a Pioneer 105 in my 700MHz eMac (following the wilko site's instructions) and I thought that was a feat. this how-to is incredible.

I could have saved a lot of money over getting a 1.25GHz PM G4 and ADC CRT.

it's great to know I could make a cheap cluster node in the future out of an 800MHz eMac. I'll soon be experimenting with whether Compressor encodes any faster with a Shake Qadministrator- created cluster. Compressor and Shake both use the same Qmaster and Batch Monitor.

if someone else out there could run the experiment that would also be great.

at school we have labs of 733 to 867 dual PM G4s, most with Shake, all with After Effects, and they aren't set up for network rendering. early next semester I'll volunteer to set up a Shake cluster throughout the lab... hopefully 2-pass VBR DVD encoding will really fly... and hopefully they have gigabit switches between all the machines.

bigbadmac
Jan 14, 2004, 01:00 AM
I'll keep you folks posted on what I get for overclocking this eMac. There are a couple of other basic mods I've done to this machine as well.

Power button is now on front under LED.
Headphone Jack is now on front between left speaker and DVD door.
Installed a Pioneer DVD-RW DVD-R 105.
Installed a 160GB Maxtor HD.

Planning a cold cathode light in the case.
Planning a LED under light to illuminate the keyboard.

I'm also interested in putting the MB in a different case... still need to work on the PS problem and pin-out on the connectors to the MB.

More to come...

lbodnar
Jan 14, 2004, 06:31 AM
Originally posted by bigbadmac
I'll keep you folks posted on what I get for overclocking this eMac...

I'm also interested in putting the MB in a different case... still need to work on the PS problem and pin-out on the connectors to the MB...

bigbadmac, that was the reason I have ended up with eMac. I was going to throw the CRT away and stick the guts into another box. However it turned out to be such a baby! :) I guess we are on the same wavelength so...

1. What is power supply "problem"?
2. Do you think motherboard CRT connector has actually standard SVGA signals and can run external monitor? I want two 19" TFTs!
3. Airport is supposed to be just a mini-PCI card with altered edge-connector. Any light in this direction?
4. What's that unpopulated connector in the middle of MB?

Enough for now!

bigbadmac
Jan 14, 2004, 11:48 AM
Originally posted by lbodnar
bigbadmac, that was the reason I have ended up with eMac. I was going to throw the CRT away and stick the guts into another box. However it turned out to be such a baby! :) I guess we are on the same wavelength so...

1. What is power supply "problem"?
2. Do you think motherboard CRT connector has actually standard SVGA signals and can run external monitor? I want two 19" TFTs!
3. Airport is supposed to be just a mini-PCI card with altered edge-connector. Any light in this direction?
4. What's that unpopulated connector in the middle of MB?

Enough for now!

1. The PS is integrated for the CRT and MB. Like the iMac, you would need to know the power requirements of the MB and the pin-out on the connectors. Once I figure this out, I can mod a common PS to run the MB. I have limited equipment here so the process is slow with a lot of Trial & Error.
2. I don't see why not.
3. This is something I was interested in some time ago. I have not found any info leading to that point but if it is nothing more than mini-PCI, it could be feasable to mod that as well to use other PCI cards... interesting subject for sure.
4. Beats me... if only I could get my hands on the MB schematic...:cool:

lbodnar
Jan 14, 2004, 12:18 PM
I have found 700MHz eMac motherboard pictures (http://218.223.20.17/em25.html). It looks very similar to 800MHz but still a bit different. However you can easily identify the speed jumpers area.

Eryan
Jan 15, 2004, 10:56 AM
If i have a 1 GHz eMac do you think it would still be stable if i over-clocked it to 1.4 GHz

applemacpunk
Jan 15, 2004, 12:54 PM
Hi guys. I'm a new user. But a long time user of several other mac forums. I saw the article on slashdot, and then found this site. Anyway I have a 700mhz eMac I would love to overclock to 750-800mhz range. Simply to meet the min. requirements for iLife 04. I have already done the Superdrive, RAM, HDD upgrade like so many others, but this would be the icing on the cake. If anyone has any success wiht this please let me know, either post here or email me. Thanks in advance.

lbodnar
Jan 15, 2004, 12:57 PM
Eryan, I think chances are 50/50. Quite possibly 800 and 1GHz models use the same processor running at different speeds. If 1GHz uses truly better CPU then the chance is very good! But in the end someone has to try. And again there is nothing certain, it all is a chance...! :)

Dont Hurt Me
Jan 15, 2004, 01:47 PM
you have become quite popular ibodnar i saw another article about what you did at applexnet Its pretty sad apple plays all these stupid games instead of trying to sell computers. If they were doing a better job at building the best machine with the best hardware they could double their measly marketshare of 3.2%. They should fire some of those bean counters and start hiring people who love macs and want macs to be the best they can be. they could have sold 1.25 emacs 6 months ago and probaly would have sold every unit they could make but instead they play their handicap game. way to go.

Rod Rod
Jan 15, 2004, 01:57 PM
<mac apologist comment>
DHM, it's Motorola's fault!
</mac apologist comment>

(that was a joke) :)

job
Jan 15, 2004, 05:32 PM
i'm a little new to soldering, so i was wondering how hard it was/is and the tools required.

can G3s be OC'ed as well?

Dont Hurt Me
Jan 15, 2004, 05:54 PM
say what you may but they do play the handicap game and end up with 3.2% market. thats the fact. Emac is still the best value and same goes with the G5s.

Anyone reading this article please be aware that most of this should only be attempted if you have electronics knowledge otherwise you could hurt your machine or yourself. should have said that sooner. static damge, electric shock etc. this isnt for the novice.

bigbadmac
Jan 15, 2004, 07:54 PM
OK kids, here goes...

I'll be tearing the eMac 700 apart this eveining and installing a jumper switch I can access from the RAM access port. This will enable me to change the jumper settings without having to open the box each time. Also will only have to solder/desolder only once.

Speaking of tools, take "Dont Hurt Me" to heart on the attemp warning. ESD is a major issue with the internal guts of your Mac. I personally recomend a good ESD Mat and ESD safe Soldering Iron. I use an iron I can control the tip temp very accuratly. It pays off when working with SMT components and IC's. The good folks at Shadio Rack...OOPS!... can get you started.

If all goes as planned, I'll set up a website with the details. I will also include the other mods as they are done and other odities I'm currently working on.

Thanks to all on this discussion group for your input... BOMBS AWAY!!!

lbodnar
Jan 15, 2004, 08:13 PM
bigbadmac, if you want to have an access without taking it apart every time, dismantle CDROM and leave perforated shield out. Assemble the case as normal and you will have eMac with the full access to guts - all you need is just to turn it over. That's how I did it.

Also, have a look here, it may be usefull (he also has 100MHz bus):
iMac 800MHz (http://www.numbski.net/2004/01/15#1-15-2004)

Please hurry up, people are killing me with questions "I-have-700MHz-eMac-can-it-be-done-too?" :D

P.S. I have uploaded more guts' pictures (http://www.lbodnar.dsl.pipex.com/eMac/eMac-upgrade.html)

Rod Rod
Jan 15, 2004, 09:27 PM
Originally posted by Dont Hurt Me
say what you may but they do play the handicap game and end up with 3.2% market.

DHM, I agree with you on this point and on a whole bunch of what you've posted in other threads. I only meant to make a joke about the people who disagree with you (the apologists).

another example of the handicap game is FCP 4's G4 only requirement. I got FCP 4 to work on my old G3 iBooks (700 and 900), using a method described by an LAFCPUG member. FCP 4 worked better and faster on my G3s than FCP 3 did. I even updated the program to 4.1.1 (using the same method) through software update. of course I couldn't get Compressor to work on a G3, and I didn't bother with LiveType, Soundtrack or Cinema Tools.

if Apple had been selling 1.25 or 1.33GHz eMacs this whole past year they'd have made a lot more money and invited many more switchers. and that would not have "cannibalized" Power Mac G4 sales. Power Mac G4s are already plenty differentiated by PCI card and HD expandability, double the RAM ceiling, dual optical drive capability and faster system bus. I bought an eMac because I couldn't afford a Power Mac, and I bought a Power Mac as soon as I could afford it because all the Power Mac's advantages.

soonbaek
Jan 15, 2004, 10:07 PM
I'm investigating if it'll be possible to overclock fsb to 133Mhz on 700Mhz eMac. So far I gave gathered info from old PowerMac G4 "Sawtooth" hack which someone has successfully converted 100Mhz fsb to 133Mhz fsb.

Scroll down (4) Bus Clock Configuration (http://www.xlr8yourmac.com/G4ZONE/sawtooth/SawtoothCPUdesign.html#osx)

After looking at the current mb, it seems there are 2 possible chips:

[1] Located right of PLL mutiplier
I'm wondering if the registers (R423, R415, R416, R424) is possible bus clock configurarion. If so de-soldering R416 and R424 should convert it to 133Mhz.

[2] Above CPU
This was suggested by Leo as possiblity. I've compared withLeo's picture on his website (http://www.lbodnar.dsl.pipex.com/eMac/pics/eMac-CPU-3.jpg) and on Leo's 133Mhz fsb mb the R303 was closed/jumped. (Could not post multiple images. see below for second image)

Anyone with 133Mhz fsb eMac mb, could you please compare the registers?

Many thanks

soonbaek
Jan 15, 2004, 10:10 PM
don't know how to attach multiple images...

Here is 2 image "Above CPU"

job
Jan 15, 2004, 10:15 PM
wow, this is getting interesting.

it seems there are a bunch of eMac users out there wanting a little more speed.

i'm surprised there isn't a larger Mac overclocking community.

Numbski
Jan 15, 2004, 10:35 PM
Just poking my head and let you know I'm watching.

I'll be opening my iMac back up to look at the mainboard when my RAM upgrade arrives, or to clock down from 1Ghz due to stability. When I do so, I'll search for possible FSB registers, post pics if I can.

In the meantime, wow I agree, this is getting interesting.

soonbaek
Jan 15, 2004, 11:23 PM
yet another pic...

This is directly back of 1st pic ("Right of PLL"). The words "UNI_INT_PCICLK" has caught my eye. :confused:

bigbadmac
Jan 16, 2004, 06:15 AM
Well kids, it works! I opted to mount a jumper connector salvaged from an old SCSI drive between the DVD IDE cable and DVD power cable. I will include a link to a website for all the details about the mod.

Anyway, this allowed me to quickly and safely change the jumpers without having to solder and desolder those itsy bitsy jumpers. Here's the skinny...

Stable at:
750MHz + + + - +
800MHz - - + + +
850MHz + - - + +
900Mhz + - - - -

The chip is rated for a max of 1GHz. Once I'm satisfied with 900MHz running stable over time, I'll clock it up to 950MHz for a while to see how it does.

More to come...

soonbaek
Jan 16, 2004, 09:02 AM
Awesome job! I like the idea of adding jumpers!

Can't wait to see how you done it. Keep up the good work :D

lbodnar
Jan 16, 2004, 09:15 AM
Actually eMac has a space for installing some sort of connector or jumpers block. Look below. Area 1 controls CPU clock. Area 2 controls something else. What? The full picture is here (http://www.lbodnar.dsl.pipex.com/eMac/eMac-jumpers-closeup.jpg).

eMacX
Jan 16, 2004, 10:30 AM
well I have an 800MHz emac based on the 7450 cpu. I bought it about 1 month before the new models that are currently available came out. I did the jumper mod, and since this emac has a 100MHz bus, things were a bit different (just math wise). The highest speed jumpering offered no video and no startup sound on power on. The next slower setting had no video, but the startup sound, but still nothing else. So this time I went with the 9x multiplier (the 1.2GHz one). We got boot! 900MHz... however it is unstable. It does boot fine if it has been off for a bit. All benchmarks and hardware tests cause it to lockup/crash. OSX runs just fine and so do any programs. Its running right now. I guess it is just too hot, or that the cpu just cant handle much above 800MHz, since that was the fastest eMac at the time. But Im thinking heat, because Im pretty sure that 7450 cpu is rated higher than 800MHz, right?. Anyways I am going to drop the speed again (think it will be 850MHz then)... its not really worth the mod. I added some thermal compound (arctic silver 5) to the heat sink/core hoping that if it was heat, maybe this would help. The heat plate is different from the one on the update page, it is pretty much totally attached to the hdd case with soldered heatpipes going from the heatsink to the hdd cage passing over two other chips (not touching them however).

It would be nice to see how you got the switch on there so I don't have to move the computer and/or take off the case everytime I need to solder/desolder.

Anyways, That was my experience... it works, but I just don't think the CPU can handle much higher than 800MHz, that or there is a heat problem.

lbodnar
Jan 16, 2004, 11:04 AM
eMacX, my conclusion is that eMac 100MHz and eMac 133MHz use very different models of CPU. The former seems to be "the fastest of the old" and the latter - "the slowest of the new". Just comparing the heatsink sizes tells it all it looks like heat is not a factor at all with 800MHz@133Mhz bus CPUs. We have to devise a reliable way to tell CPUs apart. Mine reports 7455 in XBench but in fact says 7445 on its surface (http://www.lbodnar.dsl.pipex.com/eMac/pics/eMac-CPU-2.jpg) and in terminal
LBodnar:~ lbodnar$ machine
ppc7450

Does anybody know the best software to find out all the chip details (stepping, etc)?

eMacX
Jan 16, 2004, 11:11 AM
i got ppc7450 here, and it says in big letters on the cpu, 7450. hehe

I'd be interested in a FSB mod.. but then again maybe.. if the cpu couldn't handle the new speed. Oh well... if even 850MHz doesnt work when i try later, I will go back to 800MHz.. it was fun and a learning experience.

The mac has been up for a bit now at 900MHz just kinda idle, with some apps loaded in ram. I can run xbench sometimes, others it crashes. Go Figure.

eMacX

Numbski
Jan 16, 2004, 11:22 AM
I've posted more interesting info in my blog, and I've perhaps found some help for finding the information we need to adjust the FSB, and possbily even the vcore.

Take a looksie. The guy's name is 'Tycho', and he's posted a lot at xlr8yourmac. I've posted links into the corresponding threads. I've e-mailed him and I'm awaiting a reply. Interesting reads though.

Numbski
Jan 19, 2004, 09:10 AM
Hey! I got a response from Tycho.

This could be the week my iMac gets up to 133mHz FSB. I had someone asking me about 167 on the iMac. As much as that would rock, I just don't see if happening. Even if we could, the lowest PLL Multiplier we could get is a 7.

7x167mHz = 1.17Ghz

I can't get stable at a simple 1Ghz as it is, and I've got people aspiring far beyond that already. :P

Now if a lower PLL Multiplier value were available...maybe. Then again, I still don't know if my issues are thermal or not.

applemacpunk
Jan 19, 2004, 09:22 AM
Originally posted by bigbadmac
Stable at:
750MHz + + + - +
800MHz - - + + +
850MHz + - - + +
900Mhz + - - - -

The chip is rated for a max of 1GHz. Once I'm satisfied with 900MHz running stable over time, I'll clock it up to 950MHz for a while to see how it does.

More to come... [/B]


What have your stability tests shown so far? Does the CPU seem to generate excess heat @900mhz? I'm planning on cracking mine open this weekend, but I'm not sure how far to overclock.

Plastic Chicken
Jan 19, 2004, 11:40 PM
Yes I'm an ignorant one, but where's the PLL multiplier on the 100bus MB? I don't know what exactly to look for, and I don't see what I am looking for (++-++) anywhere. Is it hidden by the heatsink or something?

Plastic Chicken
Jan 20, 2004, 02:40 PM
Oh wait, I guess it's probably on the back of the logic board...I'm somewhat reluctant to take off the heatsink (as the disassembly manuel suggests) to get to the back of the board (because I don't have any thermal grease lying around).

Is it necessary to take the heatsink off to get the logic board off? Is the PLL multiplier back there, even?

Plastic Chicken
Jan 20, 2004, 03:26 PM
I took the logic board off without removing the heatsink, seems ok.

Found the PLL multiplier too, it's fairly obvious once you look on the back of the board :)

bigbadmac
Jan 20, 2004, 03:57 PM
The site is nearly done loading. It will take some time to upload the PDF so be patient... I'm also working on a PDF version of my manual.

I'll check back here for feedback.

Overclock your 700MHz eMac to 900MHz!

BigBadMac Hakz (http://www.studio-northwest.com/Hakz/index.html)

applemacpunk
Jan 20, 2004, 04:30 PM
Very cool, thanks bigbadmac. If I read your info correctly, removing the 2nd (R1509) jumper would result in 850mhz. Removing the 2nd, 4th (R1512), and 5th (R1515) jumpers would result in 900mhz. Am I correct or upside down?

lbodnar
Jan 20, 2004, 04:44 PM
Originally posted by bigbadmac
The site is nearly done loading.

Great job! You are saving me days of answering 700MHz owners emails!
I am putting your link up right now!

A bumpy day in the air beats a calm day on the ground! Man was meant to fly.

Are you a pilot? Tomahawk and C152 here :cool:

zyuzin4
Jan 20, 2004, 06:33 PM
Tomahawk is an awesome plane, I just got my license in a Warrior/Archer. I also have a 800mhz ATI emac just got it from Apple Refurb. I'm looking to do some upgrades to it later on

bigbadmac
Jan 20, 2004, 07:29 PM
Originally posted by applemacpunk
Very cool, thanks bigbadmac. If I read your info correctly, removing the 2nd (R1509) jumper would result in 850mhz. Removing the 2nd, 4th (R1512), and 5th (R1515) jumpers would result in 900mhz. Am I correct or upside down?

You would be correct! Like I said, the real reason I installed the jumper connector was to test out the various configurations.

Numbski
Jan 20, 2004, 07:41 PM
I would love to find a slim form factor dip switch bank I could solder into my iMac so I can do a quick shutdown, flip some switches, come back up.

I don't have one handy, otherwise I'd have done it already.

Also, I haven't given up on installing that Tennmax fan on my heatpipe. I think I can do it. :) That extra cooling might just be enough.

bigbadmac
Jan 20, 2004, 10:24 PM
Originally posted by lbodnar
Are you a pilot? Tomahawk and C152 here :cool:

Navion L17 and D, C150, CozyMkIV in the works...:)

Plastic Chicken
Jan 20, 2004, 11:25 PM
BAH! Soldered it up for 850Mhz...and...

Startup sound but no picture...the air coming out the back isn't hot.

I might have fried something, although I sure hope not.

bigbadmac
Jan 20, 2004, 11:59 PM
Originally posted by Plastic Chicken
BAH! Soldered it up for 850Mhz...and...

Startup sound but no picture...the air coming out the back isn't hot.

I might have fried something, although I sure hope not.

Try the PDF from my site...eMac TS Guid and Manual (http://www.studio-northwest.com/Hakz/Resources/emac.pdf)
May just be a bad connection or something... :confused:

thedoc1111
Jan 21, 2004, 04:56 AM
Hi, I'm really interested in putting an ATI eMac in an ATX Case. The 133MHz basically seems to be an underclocked PowerMac G4 without FW800 and so I reckon (as the latest has a 7457) It could do 1.33 GHz easily (a la Powerbook 17").

But my question is, what does the blind mate connector between the digital and analog assembly do? (See the manual on L Bodnar's site: pages 34, 99 and 123) I know pins 7 & 8 supply 12Vdc, but what are the others. I don't think its video, as there is a seperate Internal video connector next to the External Video on the I/O board. I would obviously mod the eMac to an ATX supply if possible. Is all of the voltage conversion for the logic board and optical drives done from that 12V connector on the logic board by the down convertor?

I cannot find this info anywhere, but an eMac in a Lian-Li PC-50 with a SuperDrive AND a Fast Combo would be so sweet and very cheap!

Thanks for your help, and those great tutorials!

Michael

lbodnar
Jan 21, 2004, 05:14 AM
I have been looking into this. I've traced pins from the connector to the opposite side of the PCB and going to measure the voltages and document pinout soon.

Rod Rod
Jan 21, 2004, 09:18 AM
Originally posted by thedoc1111
. . . an eMac in a Lian-Li PC-50 with a SuperDrive AND a Fast Combo would be so sweet and very cheap!

or find a way to put everything in a 1-rack-unit case, paint the front a glossy white, and call it an eServe G4.

bigbadmac
Jan 21, 2004, 11:22 AM
Originally posted by thedoc1111
Hi, I'm really interested in putting an ATI eMac in an ATX Case. The 133MHz basically seems to be an underclocked PowerMac G4 without FW800 and so I reckon (as the latest has a 7457) It could do 1.33 GHz easily (a la Powerbook 17")...

Michael

Make that two of us... I've been looking at a few case mods out there for the old iMac thinking that this could be done. Any input by anyone on this would be great! I think this could be a seperate discussion though... maybe "eMac Case Mod" what do you guys think?

lbodnar
Jan 21, 2004, 11:34 AM
Makes three of us! That's how I ended up with eMac -- originally to take it apart.

Yeah, liberate your eMac!

applemacpunk
Jan 21, 2004, 12:38 PM
Originally posted by bigbadmac
You would be correct! Like I said, the real reason I installed the jumper connector was to test out the various configurations.

Which was a very smart idea. I just don't want to do that much work, so I was looking for the easiest way to get above 733. Thanks for all your input. I'll let you know how it goes.

Plastic Chicken
Jan 21, 2004, 02:33 PM
Originally posted by bigbadmac
Try the PDF from my site...eMac TS Guid and Manual (http://www.studio-northwest.com/Hakz/Resources/emac.pdf)
May just be a bad connection or something... :confused:

That's my hope, but so many things went wrong in the operation (at least 4 or 5 things that I would never repeat now that I've learned), it's only a hope. I'll tear it all apart again when I get the chance (not until Sunday), and try to clean up the solder job and make sure the connections go together correctly when I reassemble it.

What exactly does that mean? No picture, but a startupsound and the LED...I don't think it's a dead monitor.

lbodnar
Jan 21, 2004, 02:40 PM
If it all became messy try to measure resistance between pads then you will see where the "jumpers" are. Also did you plug the video cable back if you have taken it off (flat connector in the top left corner)?

Good luck!

Plastic Chicken
Jan 21, 2004, 08:08 PM
Originally posted by lbodnar
If it all became messy try to measure resistance between pads then you will see where the "jumpers" are. Also did you plug the video cable back if you have taken it off (flat connector in the top left corner)?

Good luck!

Yes I plugged the video back in. And I don't think it's a monitor problem because a) I waited for a while then hit the volume keys to listen for the beep and I didn't hear it, and b) The air coming out the back isn't warm.

And I will need luck, thank you. :)

soonbaek
Jan 21, 2004, 08:54 PM
Plastic Chicken,

My 700Mhz -> 850Mhz attempt resulted same as yours. eMac would "chime" but no video. What I believe is we have one of earlier steps of 7451 processor thus very limited in oc capability. Mine is stable at 800Mhz now.

Here are list of 7451 revisions:

XPC7451RX700CE (my eMac's rev)
XPC7451RX700CER2
XPC7451RX700RE
XPC7451RX700RER2
XPC7451RX800CER2
XPC7451RX800PE
XPC7451RX800PER2
XPC7451RX800RE
XPC7451RX800RER2
XPC7451RX800SG
XPC7451RX867PE
XPC7451RX867PER2
XPC7451RX867PG

jaybonner
Jan 22, 2004, 11:33 AM
I would try to do this but am an amatuer at motherboards... let me know what I need and what to solder and I will give it a shot.

Want to convert 700/128/40 to as high as possible with good stability

ducati
Jan 22, 2004, 10:34 PM
Exellent detail on the website lbodnar! I decided to give it a whirl last night and took my 800 up to 1066. I'm not the greatest at soldering, and my electronics bud is out of town at the moment... But the 800>1066 jump was a no brainer (just one little dollop of solder...) Perfectly stable so far... And quite a bit quicker.

I hope I can get mine running stable at 1.33, as another 266mhz boost would really make this eMac a bang-for-the-buck winner.

Like yours, I bought a leftover stock 800... Not sure of the production date, but I would assume pretty late.

Rod Rod
Jan 22, 2004, 10:40 PM
Originally posted by jaybonner
Want to convert 700/128/40 to as high as possible with good stability

the first thing you might want to do is max out the RAM. 128 is hardly helping you.

jaybonner
Jan 23, 2004, 07:56 AM
Originally posted by Rod Rod
the first thing you might want to do is max out the RAM. 128 is hardly helping you.

A good point, but we run filemaker databases and processor speed and hard drive speed are a premium... I have found that networking with OS X is slower than 9 and processor speed is very important. We have other 700 emacs with more memory, and they are faster with more memory, but not sufficiently to approach OS 9.

Rod Rod
Jan 23, 2004, 09:46 AM
Originally posted by jaybonner
A good point, but we run filemaker databases and processor speed and hard drive speed are a premium... I have found that networking with OS X is slower than 9 and processor speed is very important. We have other 700 emacs with more memory, and they are faster with more memory, but not sufficiently to approach OS 9.

my bad for guessing you were in X. it was in the back of my mind that you'd probably be in 9. I guess if virtual memory is off, and 128 is enough to run filemaker and OS 9, you're all set. 128 in OS X makes for a very crunchy sounding hard drive which of course is bad for a computer's health.

lbodnar
Jan 23, 2004, 06:29 PM
As a step towards eServe :) I have managed to measure voltages on eMac motherboard PSU connector shown here (http://www.lbodnar.dsl.pipex.com/eMac/pics/eMac-heatsink-4.jpg).
Pinout considered to be:
08 07 06 05 04 03 02 01
16 15 14 13 12 11 10 09


Pins eMac ON eMac OFF
---- ------- --------
01 02 +20.3V +12V
03 04 +12V +12V
05 06 GND GND
07 +19V +11.5V
08..12 GND GND
13 +0.3V +8V
14 +0.3V +0.3V
15 +5V +5V
16 GND GND
1,2 and 3,4 looks like high current main power
7 ???
13, 14 - control signals to/from down converter board
15 +5V TTL logic power

Anybody willing to discuss that here or in e-mail?

Plastic Chicken
Jan 24, 2004, 03:43 PM
Originally posted by soonbaek
Plastic Chicken,

My 700Mhz -> 850Mhz attempt resulted same as yours. eMac would "chime" but no video. What I believe is we have one of earlier steps of 7451 processor thus very limited in oc capability. Mine is stable at 800Mhz now.

Here are list of 7451 revisions:

XPC7451RX700CE (my eMac's rev)
XPC7451RX700CER2
XPC7451RX700RE
XPC7451RX700RER2
XPC7451RX800CER2
XPC7451RX800PE
XPC7451RX800PER2
XPC7451RX800RE
XPC7451RX800RER2
XPC7451RX800SG
XPC7451RX867PE
XPC7451RX867PER2
XPC7451RX867PG

That's encouraging, because well, I beat up my motherboard a lot (even got a static shock at one point), so that fact that yours is working at 800 is encouraging. I'll see what happens tomorrow.

Plastic Chicken
Jan 25, 2004, 08:40 PM
Back to 700Mhz and still no picture.

Here's everything bad I did to it the first time around (which I managed not to the second):

1. Used a magnetic screw driver (I thought it wasn't for a long time, because it wasn't as powerful as I'm used to)

2. Gave the logic board a really really nasty static zap one morning...I was hoping it all went into the heat sink, but...:\

3. Got one end of the jump off, then tore the other end. So tried to complete the circuit with a (relatively) large solder bridge.

4. Hit the PMU reset switch a whole bunch of times before I read that one should only hit it only once.

5. There's probably a number five, but I don't remember.

I should also note that I never removed the heatsink at all, as I have no thermal paste handy.

I guess I'll disassemble when I can and take a picture of the solder work.

Plastic Chicken
Jan 25, 2004, 09:28 PM
I've removed the battery and reset the PMU...still no video.

The battery reads about 280 mV, which I think means that the PMU did crash the first time around.

bigbadmac
Jan 26, 2004, 10:52 AM
Hey! contact me via private post. I'll be glad to get in touch with you via phone, email, AIM or whatever to help you out... The ZAP thing is bad but may not be the end of the world.

If it were me, I would clean off the solder mess and use the alternate jumper points instead... the original jumper pads are way too small AND there are other pads too close to them for my comfort... See my site for alternate jumper locations...Motherboard Prep... (http://www.studio-northwest.com/Hakz/700p5.html#)

Contact me, I'll help if I can.:)

Mav451
Jan 26, 2004, 02:44 PM
this whole thread reminds me of the excitement when i tried to overclock my Tbird back when AMD was in its infancy...

overclocking--nothing quite like it. And it doesn't even matter what platform you're on :)

'course, my Tbird was a B version and could only hit 110 fsb...you look like you got alot more luck on your side ;)

Numbski
Jan 27, 2004, 09:44 AM
Pssst. Hey guys, I think we've made some headway on the FSB issues for the 100mHz bus eMac/iMacs! :P

I need to know if the 700mHz users have that same clock chip on their boards....

http://www.numbski.net

soonbaek
Jan 28, 2004, 08:53 AM
Numbski,

I've put back my eMac but I do not remember seeing that particular chip. I do know eMac has other chips which I have posted pictures on page 2.

The main suspect at this time is the second picture (IMIC5003BY) from page 2, since I was able to compare with Leo's.

I've send a request to Cypress regarding the pinout of it.

Good job! Maybe I'll have a weekend project :D

Plastic Chicken
Jan 28, 2004, 09:00 AM
Where do you guys find this stuff?!

Numbski
Jan 28, 2004, 02:13 PM
Bah. I'm going to have to go probing the motherboard's leads to find the right resistor to remove. :( The board (according to Tycho) has 4 (!!!) layers to it, and thus I see no traces leaving the pins in question. I have to find some way to secure one of my multimeter's probes to a pin, and then go probing with the other while running a continuity test (I think).

We're now into new territory for me, so if anyone has past experience probing around like this, I'd be interested in hearing some insights.

Numbski
Jan 28, 2004, 02:18 PM
Oh, and if anyone knows of some cheap 10 switch, and 3 switch dip switch banks I can buy I'd be interested in hearing it. I didn't count the number on the eMac, but I get the feeling we could all use this.

Remember kids: Desoldering braid is your friend. As is ribbon cable. And hot glue.

and duct tape.
coffee.
a good magnifying lense.
ooh ooh! and kynar wrapping wire.
some wooden clothes pins (the spring loaded kind).

;)

Numbski
Jan 28, 2004, 02:45 PM
Bookmark me (http://www.numbski.net/2004/01/28#links)

Numbski
Jan 28, 2004, 02:54 PM
Rat Shack has an 8 switch hole-through (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=275-1301) model. You could hot glue that down sideways. Two of them would do it for the imac, leaving three switches unused. There's probably a more elegant solution though.

ducati
Jan 29, 2004, 01:47 PM
Remember kids: Desoldering braid is your friend. As is ribbon cable. And hot glue.

and duct tape.
coffee.


;) [/B]

I find scotch more effective for hand-stabilization, coffee makes me zip all over the place with the solder tip. But ya, what you said :)

Just wanted to report all is running well at 1066. I'm considering 1333 in the next few weeks... Need to get time to pick up a faster HD, might as well do that while I'm in there!

Numbski
Jan 29, 2004, 02:49 PM
Learn to love it. (http://www.pricewatch.com)

lbodnar
Jan 29, 2004, 04:51 PM
I have cut out a couple of perforated internal walls that sit right where the air flows through processor heatsink. Hopefully it will increase CPU cooling efficiency.

The other thing: after removing the speakers and leaving those holes open the EGT - OAT difference dropped from 16C to 12C. Since amount of generated heat is still the same it means the cooling fan pumps about 1/3 more air per minute. Looks like cooling efficiency leaves much to be desired.

The idea is to optimise (facilitate) the airflow and drop fan RPM to reduce noise.

lbodnar
Jan 29, 2004, 05:08 PM
Boo Apple! Leaving a hole anywhere near the speaker's moving cone effectively creates acoustical short-circuit. Low frequencies go down the drain immediately. Speakers should be mounted flush with fascia and not 1/10" away. Mounting them on rubber suspension (as they are) is also a bad idea.

It's not a HiFi but still!

lbodnar
Jan 29, 2004, 05:15 PM
Is there too much of me here? :cool:

I am fighting the temptation to put it all into pizza or 1U rack box. Features:
1.33GHz
1GB RAM
3 internal HDDs (1 system + 2 RAIDed)
DVD&plusmn;RW
2 x standard SVGA ouputs
almost silent
boots into OS 9 and OS X

I have identified space on the motherboard for network LINK, SPEED, TRANSMIT and HDD/CDdrive activity LEDs. Can also run leads and mount them on the front panel like power-on LED. No drilling needed thanks to translucent body. Anybody interested?

lbodnar
Jan 29, 2004, 05:53 PM
Solved! Follow the logic!

Investigate Soonbaek's picture (http://forums.macrumors.com/attachment.php?s=&postid=660859) of an old eMac's PLL clock IMIC5003BY.
Assume IMIC5003BY == CY28503 (numbski's datasheet is here (http://www.numbski.net/downloads/CY28503.pdf)) e.g. look at Vdd/Vss pins.
Conclude:
R301 = FSEL0
R302 = FSEL1
R303 = FSEL2

CPU/SDRAM bus frequency is:
MHZ R301 R302 R303
100 no no no
125 yes no no
133 no no yes
140 yes yes no
150 no yes no Soonbaek, just in time for the weekend:D

Numbski
Jan 29, 2004, 06:43 PM
I'm afraid I'm not following your logic here....

vdd/vss pins don't run anywhere conclusive. According to your logic, shouldn't R303 be bridged by default?

Not to mention that according to the data sheet, 133mHz should be:

no yes yes

not

no no yes

Numbski
Jan 29, 2004, 06:49 PM
Wait a sec....you're presuming 1 == UNBRIDGED on the data sheet, aren't you???

If that's the case, I need to go crack my iMac open, because I might have the 133mHz problem staring me in the face...

lbodnar
Jan 29, 2004, 06:52 PM
soonbaek shows old eMac's 100MHz bus photo, in new 133MHz eMac R303 is installed.

Datasheet columns are reversed order - FSEL2 FSEL1 FSEL0 and show logic level. Level 0 means it is pulled to the ground with the resistor/jumper.

Numbski
Jan 29, 2004, 06:57 PM
I've got it now. The table on the data sheet is backwords to what you typed up. Both ways. 0 is bridged, 1 is unbridged, and you typed it up physically backwards. Ugh. Okay, time to go tear apart my iMac. Back soon with news. :P

Rod Rod
Jan 29, 2004, 07:41 PM
Originally posted by lbodnar
I am fighting the temptation to put it all into pizza or 1U rack box.

. . .

Anybody interested?

I'm interested!

Numbski
Jan 29, 2004, 07:47 PM
Okay, I'm sitting here with my iMac open. I can't see any sets of 3 open resistors that my can pass continuity with my DMM. I'm getting the sinking feeling that it's beneath my modem, which I can't remove because it seems to take a super-small hex wrench to get at. :(

The only other area I can see that it might be is near my PLL resistors, but there are no open sets of 3 there. This is driving me nuts. That, and my camera is taking all either blurry or totally washed up pictures. a 2Mbit camera no less. ;\

I'll try to put them up anyway, i don't know what use they'll be though.

Numbski
Jan 29, 2004, 08:26 PM
The best I can do is show you my dillema from the existing images:

http://www.numbski.net/img/fsb_pins.png

As you can see, the pins don't go anywhere, and I've been probing all over the place trying to find where they spring up. :(

Plastic Chicken
Jan 29, 2004, 09:47 PM
Originally posted by lbodnar
Solved! Follow the logic!

So are you going to crank yours up to 150?

Numbski
Jan 29, 2004, 09:58 PM
I wonder....Leo, suppose I can't find the resistors. Is there anything preventing me from soldering some kynar wire to a known ground point, to a dip switch, and solder directly to the chip's pins? It'd be tight (I don't savor doing it), but it'd work, right? All we're doing is grounding the pins...

soonbaek
Jan 29, 2004, 10:29 PM
Leo,

I have same assumption as well. I have requested pin layout for IMIC5003BY to Cypress for validation.

Unfortunately, I have a wedding to attend to this weekend and I'll be out of town. :(

Hopefully Cypress will reply soon so that you guys can benefit from this discovery. Thanks for all your help guys!

Soon

soonbaek
Jan 29, 2004, 10:32 PM
Originally posted by Numbski
<snip>
That, and my camera is taking all either blurry or totally washed up pictures. a 2Mbit camera no less. ;\


Most likely you have to enable macro on your digicam to get close-up pictures. The macro setting is (on most cam) the flower symbol. Also, most digicam requires (minimum) 6-12" to focus even with macro setting. Try holding the camera back. Good luck!

Numbski
Jan 29, 2004, 10:38 PM
I had it in macro mode, but you're right. I was too close. Next time it's open I'll try backing off some.

I'm carrying on coversations in two places. I was just posting on Tycho's boards, and he just verified that I could indeed affect the FSB using the bypass method I just described. Note that I don't like the idea of doing it. Those pins are tiny and too close together for my taste. I'm really hoping he actually has that board, and perhaps can do some educated guessing so far as where to probe around. I'm flying blind in that respect. I've tried near the CPU, near what I think the clock crystal might be.

I guess I know what to do as a last resort now anyway.

Numbski
Jan 31, 2004, 03:53 PM
I've posted some hi-res shots of the iMac's mainboard. Enjoy.

bigbadmac
Feb 1, 2004, 03:00 AM
Originally posted by lbodnar
Is there too much of me here? :cool:

I am fighting the temptation to put it all into pizza or 1U rack box. Features:
1.33GHz
1GB RAM
3 internal HDDs (1 system + 2 RAIDed)
DVD&plusmn;RW
2 x standard SVGA ouputs
almost silent
boots into OS 9 and OS X

I have identified space on the motherboard for network LINK, SPEED, TRANSMIT and HDD/CDdrive activity LEDs. Can also run leads and mount them on the front panel like power-on LED. No drilling needed thanks to translucent body. Anybody interested?

O-yea!!! This is one I would love to do... : )

lbodnar
Feb 1, 2004, 05:53 PM
Numbski! I am pleased to announce the location of iMac's CPU bus setting resistors! Tadammm!

They are under SODIMM module!

FSEL0 0=R627 1=R625
FSEL1 0=R635 1=R628
FSEL2 0=R637 1=R636

The bad thing is that on my Flat Panel iMac the whole PLL chip is missing so you are lucky!

Plastic Chicken
Feb 1, 2004, 07:06 PM
reverse engineer extraordinaires

wow guys

What say you/we figure out how to OC every Mac CPU and bus and make a website?

Numbski
Feb 1, 2004, 09:59 PM
WTF??? Under the sodimm? :P

Okay, okay. So Leo, beverage of your choice. Give me an address and it's all yours. :)

Sometime tomorrow I'll take down my machine and run some jumper wires. Then the fun will begin.

I'd have done this already, but I haven't found any good dip switches to use. Looks like I'll be using Radio Shack's.

This'll be fun. :)

Numbski
Feb 1, 2004, 10:30 PM
Just for clarification, you highlighted 6 pairs. In order to change the setting, it's not a matter of on or off, you have to move the resistor from one location to another? Just a little confused as to how this is supposed to work out.

Thinker
Feb 1, 2004, 11:14 PM
Originally posted by Numbski
Just for clarification, you highlighted 6 pairs. In order to change the setting, it's not a matter of on or off, you have to move the resistor from one location to another? Just a little confused as to how this is supposed to work out.


I think so, just as the way "resistor bank"(http://www.numbski.net/2004/01/15#1-15-2004) for CPU's multiplier.;)

bigbadmac
Feb 1, 2004, 11:24 PM
Originally posted by Numbski
WTF??? Under the sodimm? :P

Okay, okay. So Leo, beverage of your choice. Give me an address and it's all yours. :)

Sometime tomorrow I'll take down my machine and run some jumper wires. Then the fun will begin.

I'd have done this already, but I haven't found any good dip switches to use. Looks like I'll be using Radio Shack's.

This'll be fun. :)

Check out Digikey. They cary a huge supply of DIP Switches, not to mention EVERYTHING else you could ever want... Digikey DIP Switches (http://www.digikey.com/scripts/DkSearch/dksus.dll?Criteria?Ref=176468&Site=US&Cat=31589419) :D

lbodnar
Feb 2, 2004, 02:39 AM
:) Numbski, I'm glad we are moving forward!

In theory you might need to ground only FSEL0 to get 125MHz and FSEL2 for 133MHz so the first thing to do is to measure resistor values for R625 and R636. If they are zero then you would need to move them to R627 and R637 respectively. But if they are something between 1kOhm and 10kOhm, then they will act as typical pull-up resistors and you will only need to short R627 and R637. Even more since the ground wire is the same you might get away with only three wires and two switches.

Do you get the idea?

Measure the resistance first! Hell, it is all a theory yet! Can you confirm that you have R625 R628 and R636 mounted on yours? If yes, all the rest is OK.

The same thing applies to main CPU speed settings. You can have 1-10kOhm pull-ups and just ground frequency selection pins when needed with a simple switch.

I just had a look at CY28503 datasheet - it already has internal 250KOhm pull-up resistors. Quite high resistance though... Maybe external ones are needed to make sure it will survive nuclear explosion EMI? :)

lbodnar
Feb 2, 2004, 03:05 AM
Do I get it right that Apple seems to have two sorts of FP 800MHz iMac - one is just that and the other is "133MHz ready"? Japanese pictures and my iMac have the whole bus clock PLL chip missing and Numbski has it?!

The other thing - if I recall correctly from PC days, the CPU has a better chance to run at specific speed with higher bus speed and lower clock multiplier than at lower bus speed. Is it correct?

If stability is just the heat dissipation issue then it should not matter as Mototola documentation and common sense says that heat dissipation is approximately proportional to the processor speed. Even more the bus subsystem runs at higher speed too so there should be even a little bit more heat at 133MHz bus.

However internal CPU PLL comparator circuit will run at lower ratio so the chance of having a glitch there is lower too. It is actually quite interesting, WHAT exactly causes glitches in CPU at a too high speed?:confused:

Numbski
Feb 2, 2004, 09:18 AM
I don't have answers to several of your questions I'm afraid. I went out and bought my 800 almost immediately after they came out, so I'm at a bit of a loss as to why some seem to be ready for a 133mHz FSB (replete with PC133 RAM as opposed to PC100) and others are missing that chip altogether.

Nor can I answer about the glitches at higher speeds. You are correct that higher FSB/lower multiplier is usually more stable, at least in PC's. The first thing I'm going to do is move the multiplier down to 7x and bump the FSB to 133mHz. That's still going to be a higher speed than where I'm at now though, which is 900mHz, up to 933mHz.

I'll be able to verify what's mounted where under the sodimm this afternoon. I have a silly question though: the only thing I ever use my multimeter for is continuity testing. I know, I know, that's still, but it's true. Can I test resistance using that? :P I'm a network engineer, not an electrical one.

davida
Feb 2, 2004, 11:32 AM
Ok. I am not a techie and I am a little lost. I have a 700iMac and would like to know : is there a way to overclock it higher as well?

thanks,
davida

Numbski
Feb 2, 2004, 11:43 AM
I'm not sure. You'll need to look at your motherboard. Look to see if it's the same board as the one in my pictures. If it is, then check the multiplier registers and compare them to my table. If they match, then finally check to see if the clock chip is there. If it is, then more than likely it can.. :)

I'm sitting at 9x multiplier and 100mHz FSB right now, or 900mHz. This evening I'm hoping to try 7x multiplier and 133mhz FSB, which is 933mhz.

In theory (no way to know if the cpu supports it or not) the iMac has the same range and tolerances as the eMac, giving us 1.4Ghz. Actually, that clock chip allows for a 150mHz
FSB, and a 10x multiplier is possible, giving us 1.5Ghz, but without outboarding the SuperDrive to an external firewire enclosure, and possibly using a peltier cooler, I'm not sure this will be possible.

But to show you my persuasion, I already have the external enclosure lying in wait and some links to peltier coolers in my bookmarks. ;)

lbodnar
Feb 2, 2004, 03:11 PM
Just tried to push my 1.33GHz eMac's FSB to 140MHz and it did not boot at 1.4GHz at all. Just was beeping and blinking its LED. I think the memory did not pull it off. Well I do not object. It "almost" works on1.4GHz at 133MHz FSB (hangs after 10-15min under heavy load). So most probably it is the memory issue.

By the way I have initially used 10kOhm resistors instead of shorts and ended up with a 100MHz FSB (=all three jumpers removed) so basically it is what 700 and 800MHz non-ATI eMac are. This is just proves that to get 100MHz->133MHz you need to short circuit R303 (http://forums.macrumors.com/attachment.php?s=&postid=660859) - do not bother soldering a resistor there (I have removed it, then accidentally lost it and ended up simply shorting it with some extra solder.)

soonbaek
Feb 2, 2004, 04:47 PM
Whoo~hoo~

Once again, thank you! I'm glad I got to be part of this exciting discovery.

soonbaek
Feb 4, 2004, 06:38 PM
Cypress has replied back with the pinout for eMac. As Leo has already pointed out, it is indeed the chip!

Unfortunately, it is too big to attach. Would anyone willing to host it? *cough* Numbski *cough* :D

lbodnar
Feb 4, 2004, 07:41 PM
I have made iMac's 800MHz logic board scans. Click on the icons to see full-size pictures. It features my wallet as a prop. :p

http://www.lbodnar.dsl.pipex.com/eMac/pics/s-iMac-up.jpg (http://www.lbodnar.dsl.pipex.com/eMac/pics/iMac-up.jpg) http://www.lbodnar.dsl.pipex.com/eMac/pics/s-iMac-bottom.jpg (http://www.lbodnar.dsl.pipex.com/eMac/pics/iMac-bottom.jpg) http://www.lbodnar.dsl.pipex.com/eMac/pics/s-iMac-CPU-bus.jpg (http://www.lbodnar.dsl.pipex.com/eMac/pics/iMac-CPU-bus.jpg)

Anybody willing to host them?
*cough* Numbski *cough*
*cough* bigbadmac *cough*:D

lbodnar
Feb 5, 2004, 04:23 PM
Does anybody have any idea of what unpopulated connectors could be?
http://www.lbodnar.dsl.pipex.com/eMac/pics/s-iMac-bottom.jpg (http://www.lbodnar.dsl.pipex.com/eMac/pics/iMac-bottom.jpg)
This huge 140 pins J23 looks like it is sitting right on the system bus. Since it is on the bottom of the board I assume it is for preproduction samples testing only unless Apple plans to use this logic board in a ball shaped Mac :)

Experience shows that unpopulated connectors could hide some goodies, like serial ports or S/PDIF digital sound output...

Also can you spot outputs for network receive, link and speed LEDs, disk activity LED and RESET and NMI switches? :D

Numbski
Feb 6, 2004, 10:42 AM
If I had to wager a guess, I'd say compact flash.

I don't remember how many pins are on a compact flash interface, I'd have to go look it up.

lbodnar
Feb 6, 2004, 11:02 AM
Originally posted by Numbski
If I had to wager a guess, I'd say compact flash.

I don't remember how many pins are on a compact flash interface, I'd have to go look it up.

Only about 50 :p click->http://www.lbodnar.dsl.pipex.com/s-CF-128.jpg (http://www.lbodnar.dsl.pipex.com/CF-128.jpg)

Numbski
Feb 6, 2004, 03:58 PM
Next guess is mini-pci then. :P

lbodnar
Feb 7, 2004, 03:17 PM
Somebody was asking for the pinout of the power switch (J4503). I turns out it is simply a push-button. Going clock-wise from the key pin (bottom-right):

1 - Connection cable shield (thick black)
2 - no connection
3 - power on switch (red) +
4 - power on switch (thin black) -

pins 1, 2, and 4 are all grounded on the logic board
bushbutton switch is connected between 3 and 4.

dan2001
Feb 10, 2004, 06:58 PM
Has anyone overclocked their 800GHz iMac to 1.33GHz? If so, how did you do it?

Dont Hurt Me
Feb 10, 2004, 07:13 PM
I think you need to start at page 1 Vern:confused:

Numbski
Feb 11, 2004, 09:14 AM
I've been kinda quiet. I haven't had a chance to mess with the iMac's FSB connections under the SODIMM socket. Been very busy.

Maybe this week? I'm still trying to figure out how I'm supposed to get 3 groundable pins out of 6 pairs of solder points. Leo never did clear that one up for me. :P

Plastic Chicken
Feb 11, 2004, 02:21 PM
Alright guys, look for the multipliers and junk...

http://homepage.mac.com/dabaer/PhotoAlbum8.html

Numbski
Feb 11, 2004, 04:24 PM
http://homepage.mac.com/dabaer/.cv/dabaer/Sites/.Pictures/Photo%20Album%20Pictures/2004-02-08%2007.06.47%20-0800/Image-86B610AB5A4611D8.jpg-thumb_140_105.jpg

Need that shot to be larger and clearer.

Also need to find the clock chip, and the G5 (IBM 970) data sheet for what we'd need to be looking for as far as multiplier goes...

Plastic Chicken
Feb 11, 2004, 06:06 PM
Of course, if none of us here has a G5, it's not worth much...

Although the VTech G5's are on sale for $2800 at MacMall, so if anybody wants one now...

lbodnar
Feb 11, 2004, 07:05 PM
Originally posted by Numbski

Need that shot to be larger and clearer...



G5 CPU (http://homepage.mac.com/dabaer/.Pictures/Photo%20Album%20Pictures/2004-02-08%2007.06.47%20-0800/Image-86B697C35A4611D8.jpg) closeup. Is that what you are looking for? :) Obviously CPU multiplier should be located on a CPU plug-in board not motherboard itself.

lbodnar
Feb 11, 2004, 07:11 PM
This is most probably the itchy spot.

Plastic Chicken
Feb 11, 2004, 08:13 PM
You guys are amazing...

How'd you guess? Teach me your secrets!

Plastic Chicken
Feb 11, 2004, 10:08 PM
Originally posted by Numbski Also need to find the clock chip, and the G5 (IBM 970) data sheet for what we'd need to be looking for as far as multiplier goes... [/B]

Can't find anything on IBM's main site, only an overview presentation...

I don't think such a thing exists, publicly.

Numbski
Feb 12, 2004, 07:39 AM
Originally posted by lbodnar
G5 CPU (http://homepage.mac.com/dabaer/.Pictures/Photo%20Album%20Pictures/2004-02-08%2007.06.47%20-0800/Image-86B697C35A4611D8.jpg) closeup. Is that what you are looking for? :) Obviously CPU multiplier should be located on a CPU plug-in board not motherboard itself.

Bah, I had my brain in iMac land, where the cpu is on the mainboard. I was really tired when I made that post.

I need to convince my wife to let me have some iMac downtime to get my multiplier set up today.

Thinker
Feb 14, 2004, 02:27 AM
Inspired by lbodnar's article (http://www.lbodnar.dsl.pipex.com/eMac/eMac-upgrade.html), Numbski's link (http://www.numbski.net/journal/imac_hack) and discussion on this thread, I manage to overclock my iMac FP 17 inches 1G Hz to 1.27G Hz (via changing CPU's multiplier from 7.5x to 9.5x under FSB 133MHz). Here is my iMac's mainboard picture with detail location of resistor bank.

R374 R376 R378 R379 R382 ---> left column resistors on picture
7.5x + - - - -
8x - - + + -
8.5x - + + - -
9x + + + - +
9.5x + + + - -
10x - + - + +

+ : with resistor
- : without resistor

For the right column resistors R375, R377, R380, R381, R383 it is simply "inverse" of left column, i.e. For each row the resistor located either on left side or on right side.

Put in another way:
===================
According 7455 datasheet (http://e-www.motorola.com/files/32bit/doc/data_sheet/MPC7455EC.pdf) page 47,48 : CPU's Bus-to-Core Multiplier table. For example, if you want 7.5x the PLL_CFG[0:4] column is "00010" with order "Bit 5, Bit 4, Bit 3, Bit 2, Bit 1" than only "Bit 2" set to "1", That mean R374 should mount a resistor (so R375 need not mount resistor) ....

R374,R375 ---> Bit 2
R376,R377 ---> Bit 3
R378,R380 ---> Bit 4
R379,R381 ---> Bit 5
R382,R383 ---> Bit 1

My ambition is raise FSB from 133MHz to 167MHz, since higher FSB mean higher performance with same CPU speed. But without new iMac (167MHz FSB model) mainboard picture for compare, I can't go any further :(
Could someone provide or point me to these new iMac mainboard picture? Thanks.

ziess
Feb 15, 2004, 12:57 PM
Long live eServe!
I'll do it if someone will give full instructions and a parts list.
Do you think it would be possible to use the eMac CRT monitor as a monitor if it were mounted in the original case?
Does the original type 700 Mhz eMac have dual independent ide channels like the new type 800 Mhz version? If so one of these mounted in a rack server case at around 1 GHz running with some serious cooling could basically be an eServe, albeit witha lower bus speed...
Interestingly, http://developer.apple.com/documentation/Hardware/Developer_Notes/Macintosh_CPUs-G4/eMac/eMac.pdf

notes on page 36 that the Airport card is in fact mini PCI based so, theoretically speaking, it would be just possible to get this hooked up to a normal PCI slot and run a PCI card in it, wouldn't it?
Also, would it be possible to run dual monitors by taking a feed off the internal monitor wiring as the first eMacs don't support software modification. Someone raised this already but I dunno what the answer was. This was definetly the case with the first iMacs (G3) which hooked up to the monitor with, wait for it, a VGA connector and could be made to support spanning by running a lead out from the VGA lead to a second monitor.
Anyway.
Keep it up guys! This is exciting!

Numbski
Feb 16, 2004, 08:59 AM
I don't think mini-pci has all of the same lines as standard pci...I'm trying to remember off-hand what the differences are. Some will work, but only the ones that don't utilize the extra traces.

The other problem becomes of course driver support for whatever pci device you're wanting to plug in.

mimacx
Feb 19, 2004, 04:50 PM
I've been looking at the g3 350mhz imac and find out something on the board that could be the pll clock signal chip.

It as the reference IMI C5002BYB 0032 T3010

Anyone know what can be done with this?

mimacx
Feb 19, 2004, 05:03 PM
i found ibm info for the processor at http://www-3.ibm.com/chips/techlib/techlib.nsf/products/PowerPC_750_Microprocessor_(300MHz_to_550MHz)

mimacx
Feb 19, 2004, 05:06 PM
And the multiplier settings at http://www.bekkoame.ne.jp/~t-imai/imacde1.html

lbodnar
Feb 19, 2004, 05:50 PM
Have lately attached one of those variable fan speed controllers (http://www.maplin.co.uk/products/module.asp?moduleno=32310&Products=1) to my 800->1.33 eMac's fan. Set it for nearly silent operation (quiter than HDD + internal PSU humming). At room temperature (OAT) 22C exhaust air (EGT) has increased from 35C to 43C. I have no adverse effect on stability at virtually silent operation @ 100% load!

I just love those eMacs!:D

mimacx
Feb 20, 2004, 04:22 PM
This mac uses the motorola XPC755A processor http://e-www.motorola.com/files/32bit/doc/data_sheet/MPC750EC.pdf

mimacx
Feb 21, 2004, 01:10 AM
I found some info on this japanese page about imac DV http://www.bekkoame.ne.jp/~t-imai/imacdj3.html

Phillip
Feb 21, 2004, 05:58 AM
that was a great article :D

i want an emac over my imac 15" now... :(

can i over-clock my imac 15" 700 g4???

maxpayne.co.uk
Feb 21, 2004, 10:55 AM
Lbodnar, I think you should create one massive eMac modding site :D

(I really want an eMac...)

x86isslow
Feb 21, 2004, 11:48 AM
Do you mean other than this (http://www.lbodnar.dsl.pipex.com/eMac/eMac-upgrade.html) site?

maxpayne.co.uk
Feb 21, 2004, 12:23 PM
Originally posted by x86isslow
Do you mean other than this (http://www.lbodnar.dsl.pipex.com/eMac/eMac-upgrade.html) site?

Keep that.....and just include all the little bits like the fan mod.

Add stuff like how to replace the HDD, etc, and maybe a tweaking guide.

mimacx
Feb 24, 2004, 07:25 AM
I think these are the FSEL for this chip but i'm not shure about the FSEL order...

mimacx
Feb 27, 2004, 10:56 AM
Here's the pdf http://homepage.mac.com/dgiessel/.Public/c5003.pdf

The settings for bus speed... ;)

Plastic Chicken
Mar 9, 2004, 05:12 PM
With much thanks to BigBadMac, my eMac works again!

CubeHacker
Mar 9, 2004, 11:06 PM
With much thanks to BigBadMac, my eMac works again!

What was the problem? Seems your eMac was dead for like a month!

h8full1OSU
Mar 10, 2004, 10:58 AM
Kinda new to macs and not very familiar with the "technical" end of things. I'm not going to get a new mac until fall and would like to put a little more life into my eMAc. Any suggestions would be appreciated in helping me facilitate this hack.

bigbadmac
Apr 7, 2004, 12:17 AM
I've put up a site for all of us 700 eMac users... http://www.studio-northwest.com/Hakz/index.html

mydany
Apr 14, 2004, 09:46 PM
Thanks Ibodnar. I have 1ghz emac now running at 1.27 ghz with no problems!! I also installed a new 120 gig western digital hard drive and installed a pioneer dvd burner. My xbench score is 119 up from 100!!! Any one know how to get more performance from the video card or even make increase the bus from 133 to 167????? Thanks again.

windowsblowsass
May 23, 2004, 07:25 PM
any one know if its possible to change the graphics card in the emac the radeon 7500 is a little slow would it be possible to pop a new video card in the agp slot

bigbadmac
May 25, 2004, 12:23 PM
any one know if its possible to change the graphics card in the emac the radeon 7500 is a little slow would it be possible to pop a new video card in the agp slot

Actually, there are no AGP or PCI "slots". The graphics chip is soldered directly to the MB. Sorry...you got what you got...be happy! :rolleyes:

Numbski
May 26, 2004, 11:23 AM
Hey guys, I'm back!

Did you miss me? I know you did. :P

I didn't get a chance to clock up the bus speed on the imac 800 yet. I got evicted, then started to buy the house, then got evicted again, bought another house (3 weeks till closing), moved out of state, and after closing I'm moving back!

I just got my hands on a 233 Bondi, and I'm going to be overclocking it as well . :) It's going to my sister and her kids, so the soldering iron is back on the prowl again, and after seeing the CPU daughter card for the Bondi, I think I finally understand what I need to do to finishing clocking up to 1.33Ghz on the 800, but I get the sinking suspicion that a peltier cooler and possibly an external power supply will be required. I think I'd just be thrilled with ~900mHz@133mHz frontside bus.

Anyway, I'm back on the case. :) Also considering upgrading to a G4 433 in the bondi, and then trying to overclock from there. Who knows?

JLaFrance
May 26, 2004, 08:33 PM
sounds alittle risky to me..i couldnt afford to screw up...

Anarchy99
Jun 9, 2004, 06:36 PM
i was wondering can you overclock the 1.25 ghz emac and what to

windowsblowsass
Jun 9, 2004, 09:41 PM
Actually, there are no AGP or PCI "slots". The graphics chip is soldered directly to the MB. Sorry...you got what you got...be happy! :rolleyes:
according to an apple history webpage forget whitch one
there is 1 agp slot that is filled with a vid card i dk if this is true but i was hoping someone who was more familiar with inside the emac could help me i dont want no stinking 7500m

Mord
Jun 11, 2004, 04:04 AM
according to an apple history webpage forget whitch one
there is 1 agp slot that is filled with a vid card i dk if this is true but i was hoping someone who was more familiar with inside the emac could help me i dont want no stinking 7500m

7500's are decent live with it


there is an agp bus on an emac but the card is part of the logic board so unless you feel like finding the circet traces soldering on an agp slot and modding the emac so one fits and dose not overheat live with it

Anarchy99
Jun 11, 2004, 08:09 AM
can i mod a emac 1.25ghz to 1.3 or higher or is this only for 800mhz,1ghz
has anyone tried

bigfatlamer
Jun 11, 2004, 04:12 PM
Has anyone given the solder-less overclocking a shot on the G4 iMacs?. Is there anything that can be used as a jumper rather than soldering?

Also, does anyone have a good link for changing the FSB on these machines? The ones I've found in this thread are all fscked.

Great thread. I'll keep watching. I'd love to do a little overclocking but my soldering skills aren't good enough to try on my main machine.

TIA,
BFL

Anarchy99
Jun 12, 2004, 02:12 PM
solder-less overclocking?

Jigglelicious
Jun 12, 2004, 03:50 PM
Has anyone given the solder-less overclocking a shot on the G4 iMacs?. Is there anything that can be used as a jumper rather than soldering?

Also, does anyone have a good link for changing the FSB on these machines? The ones I've found in this thread are all fscked.

Great thread. I'll keep watching. I'd love to do a little overclocking but my soldering skills aren't good enough to try on my main machine.

TIA,
BFL

Electronic stores might sell something called a Conductive pen/pencil, which allows you to bridge 2 connections easily without having to use solder. There are people that even used to use the 'pencil trick' (basically an ordinary lead pencil) on Athlon CPUs to connect the bridges to allow for overclocking, but I attempted that on my eMac and it didn't work - I was forced to use solder. Using solder isn't as dangerous as it sounds, since you can easily remove it using solder wick. The tricky part is removing those microscopic jumpers that they use to set the CPU speed!

Numbski
Jun 16, 2004, 06:49 PM
There are silver trace pens, and now that you mention it, that's a perfect solution.

In theory.

You'd better be sure that's what you want though, because I have no clue as to how you 'undo' a silver trace pen. With solder, you use desoldering braid.

No, the right way to do this really is to get ahold of a jumper bank or a set of dip switches from DigiKey and solder that on. Then play to your heart's content.

Ideally you do this to a ribbon cable and run it to the outside of the machine so you don't have to tear down for each change. Ideally.

frescies
Jun 19, 2004, 11:18 AM
Hey guys, I'm back!

Did you miss me? I know you did. :P

I didn't get a chance to clock up the bus speed on the imac 800 yet. I got evicted, then started to buy the house, then got evicted again, bought another house (3 weeks till closing), moved out of state, and after closing I'm moving back!

I just got my hands on a 233 Bondi, and I'm going to be overclocking it as well . :) It's going to my sister and her kids, so the soldering iron is back on the prowl again, and after seeing the CPU daughter card for the Bondi, I think I finally understand what I need to do to finishing clocking up to 1.33Ghz on the 800, but I get the sinking suspicion that a peltier cooler and possibly an external power supply will be required. I think I'd just be thrilled with ~900mHz@133mHz frontside bus.

Anyway, I'm back on the case. :) Also considering upgrading to a G4 433 in the bondi, and then trying to overclock from there. Who knows?



Hey Numbski,
I've been tracking your progress on your 800 mhz imac (same model as mine) and I'm really curious to hear your latest progress. Also, what do you have in mind in regards to the use of a peltier? I have a peltier lying around and I'm curious about the heat dissipation possibilities. I wonder if the coper pipe can carry enough heat away. Or, perhaps I can route a different heat pipe/sink in addition to the peltier. I'm curious to hear your thoughts on this :D

neoelectronaut
Jun 26, 2004, 04:19 PM
I'd love to try to bump by 1 Ghz eMac up to 1.33Ghz when the applecare runs out, but I've done very little soldering, and I'd probably screw something up. Also, the whole - + - thing is confusing the crap outta me.

Luap
Jul 5, 2004, 09:35 AM
I'd love to try to bump by 1 Ghz eMac up to 1.33Ghz when the applecare runs out, but I've done very little soldering, and I'd probably screw something up. Also, the whole - + - thing is confusing the crap outta me.

I did this mod to my 1ghz eMac (Bought in September 2003).. At 1st I went to 1.33ghz, and it worked, but quite consistently it would freeze after about an hour's heavy use. With minimal loading, it was fine however. But of course the freezing bugged me and it was almost certainly caused by me modding it.
So recently I took it down a bit to 1.2ghz and also used some costly silver based heat transfer compound for the cpu-heatsink.
And now it's working 100% perfectly (Or should that be 120%? :D ). Of course I do now wonder if the new silver based heat transfer compound might have let it work at 1.33ghz after all!? But for now I'm perfectly happy with a 1.2ghz eMac. Still a virtually free 20% speed boost. So can't grumble :)
Also, didn't I read somewhere that lbodnar now runs his eMac at 1.46ghz?? Thats amazing considering it was an 800Mhz eMac to start with! So a bit strange that my 1ghz is reluctant to go past 1.2ghz then, but no matter..
Oh, and I also did the screen spanning hack on mine. I did this the same day I bought it, and this also works perfectly :)
Good luck guys!

Luap
Jul 5, 2004, 09:44 AM
Oh, and while i'm here.. Really, you do need some good soldering experience to do this mod. Regular soldering can be tricky enough, But this surface mount stuff really is fiddly! My heart sank when I 1st saw how tiny the jumpers were. Not far off the size of a grain of sand or 2! :eek:
But still, I went ahead and got the job done.
lbodnars site was an excellent help!

Personally, I'd not recommend using a lead pencil! Or even the conductive paint stuff..

Numbski
Aug 5, 2004, 09:06 AM
Big huge freaking *BUMP* :)

Okay, okay. I'm horribly unrelliable. Who knew? :P

Anyway, I'm been moving a lot. Like twice in 3 months. My iMac is sitting at my data center since it acts as my e-mail and web server, not just my desktop. Terrible infrastructure, working to fix it, but for the moment, that's how it is.

Anyway, could anyone who's a bit more familiar with <a href="http://www.digikey.com">DigiKey</a> give me a hand with nailing down a pair of dip switch banks that are pretty smallish? I'd like to set up one to handle the multiplier, and the other to handle the FSB, and then either tape or hot glue them next to the ram upgrade socket for easy adjustment.

Initially I may even outboard them. The plan is to do this when I'm ready to move hte mac into the new house, which will be after my carpet is instålled, which is a week from monday. :)

wernerru
Aug 16, 2004, 04:36 PM
Hello all, i just took my 133 fsb 1ghz eMac up to 1.6 by popping all but the second jumper off... jumped to 1.6ghz as the datasheet says for 12x, and it's been running under 100% load since then, compiling fink binaries, itunes ripping, and photoshop filters on a 2gb file. I'd say it's worth it, even tho i almost choked when i saw how small the resistors are :eek: . Thanks again lbodner for writing the how-to!

mkaake
Aug 16, 2004, 05:08 PM
Hello all, i just took my 133 fsb 1ghz eMac up to 1.6 by popping all but the second jumper off... jumped to 1.6ghz as the datasheet says for 12x, and it's been running under 100% load since then, compiling fink binaries, itunes ripping, and photoshop filters on a 2gb file. I'd say it's worth it, even tho i almost choked when i saw how small the resistors are :eek: . Thanks again lbodner for writing the how-to!

was that a 1.0 or a 1.25 from the factory?

zyuzin4
Aug 16, 2004, 05:54 PM
Hello all, i just took my 133 fsb 1ghz eMac up to 1.6 by popping all but the second jumper off... jumped to 1.6ghz as the datasheet says for 12x, and it's been running under 100% load since then, compiling fink binaries, itunes ripping, and photoshop filters on a 2gb file. I'd say it's worth it, even tho i almost choked when i saw how small the resistors are :eek: . Thanks again lbodner for writing the how-to!



wow

im still waiting to OC my 800mhz eMac and have been wanting to since this thread opened

wernerru
Aug 16, 2004, 06:25 PM
was that a 1.0 or a 1.25 from the factory?

1.0 stock. It's been running since midnight at 100% load like i said, hasn't hit a hiccup yet compiling. Apple-made apps open almost instantly, terminal's up before you can even let go of the button. i could do the 2ghz route by going to the 15x multiplier by bridging two more... but i don't feel like having to take them off if it doesn't work... or worse yet, turning it into a pile of slag. but, this working supports everyones' thoughts that the emacs are just underpowered to limit them from hurting the top-end lines. i'd say the 1.25 factory new models (with the 167 bus) could easily break the 2ghz, since it's the fsb that moved it from 1.0ghz to 1.25 at the 7.5x. going to the 12x like mine on the 1.25 would make a 2.0ghz machine.

OziMac
Aug 16, 2004, 06:37 PM
I am the same - want to do this, but don't have any soldering experience. Any suggestions on ways to get experience doing this? I have a few old decommissioned computers lying around to practice on but no real idea how to get started...

wernerru
Aug 16, 2004, 06:39 PM
I'd love to try to bump by 1 Ghz eMac up to 1.33Ghz when the applecare runs out, but I've done very little soldering, and I'd probably screw something up. Also, the whole - + - thing is confusing the crap outta me.
haha, oops... just realized i had a 3 year applecare. if you've got any questions, you can email me if you want. As for the soldering, it's not supremely hard, but going to the 1.33 means having to solder onto the dry pad in the number 4 spot. i just took an exacto knife, and pressed into the solder on the bottom connection of the jumpers, and then pushed a little and twisted, and they come right off, leaving the solder on the pads, meaning if it needs to go back, you just hit it real quick with a soldering iron, and it's back to 1.0. any questions, from anyone, about most anything, welcome to email at wernerru at msu.edu

wernerru
Aug 16, 2004, 06:42 PM
I am the same - want to do this, but don't have any soldering experience. Any suggestions on ways to get experience doing this? I have a few old decommissioned computers lying around to practice on but no real idea how to get started...
if you want to go to 1.6ghz, do what i just posted above, about using the xacto knife to pop off the top, 3rd, and bottom jumper, leaving the number two spot shorted. it's really easy too, because all you have to do is take the case off, the faraday plate, and then the optical drive (cd, dvdrw, whichever), and it's right under there

as for testing it out, find an old board in your pile, and just try removing a surface mounted component, like a flat capacitor or a bigger resistor, till you can do it without ruining the board, and then work down in size. keep in mind these things are absurdly tiny!

mikeyredk
Aug 16, 2004, 06:45 PM
wernerru what is your heat output? use thermograph (http://www.macupdate.com/info.php/id/13019) if you can i don't know if your cpu is supported

wernerru
Aug 16, 2004, 06:53 PM
wernerru what is your heat output? use thermograph (http://www.macupdate.com/info.php/id/13019) if you can i don't know if your cpu is supported
doesn't report it, says there's no sensor found. i don't think the TAU on the chips work in the eMacs. didn't work before i did the OC either. but by the hand-behind-fan judgement, it's not too much warmer, and using a digital thermo, it's only a few degrees warmer.

Russ

mikeyredk
Aug 16, 2004, 07:03 PM
thx now to find a cheap emac :D

OziMac
Aug 16, 2004, 07:10 PM
Yeah, do you have heat issues with your CPU running at that speed werneru?

wernerru
Aug 16, 2004, 07:11 PM
thx now to find a cheap emac :D
check apple's reconditioned page, they have things there all the time, just reload it a few times a day

wernerru
Aug 16, 2004, 07:13 PM
Yeah, do you have heat issues with your CPU running at that speed werneru?
the only issue i have, and have ever had with it, even stock, is the fan being single-speed LOUD. i was going to put either a pot in there or a fan controller to make it quieter, but now that i'm pushing the 1.6, i don't think it'd be prudent :D

mkaake
Aug 16, 2004, 07:38 PM
this is way to tempting. i have a nice 1.0 sitting right in front of me, with the possibility of a 60-100% increase in clock speed. too bad its the only computer we have right now (save my growing collection of older macs), and I can't' really afford to screw it up :(

but someday, this emac will fly....

someday.

wernerru
Aug 16, 2004, 07:44 PM
this is way to tempting. i have a nice 1.0 sitting right in front of me, with the possibility of a 60-100% increase in clock speed. too bad its the only computer we have right now (save my growing collection of older macs), and I can't' really afford to screw it up :(

but someday, this emac will fly....

someday.

i still want to try to take it to 2.0ghz... but with my luck it'd boot and slag, and then i'd have A LOT of explaining to do about why the computer they just bought for me to replace the other 3 that have died over the years (all powerbooks). i think 1.6 is about as far as i'm willing to risk it. on the other hand, if the chips in the 1.25ghz stock machines are the same, just with the resistors set at 167 fsb instead of 133, i'd change it to 167 in a heartbeat.
Russ

mkaake
Aug 16, 2004, 07:57 PM
i still want to try to take it to 2.0ghz... but with my luck it'd boot and slag, and then i'd have A LOT of explaining to do about why the computer they just bought for me to replace the other 3 that have died over the years (all powerbooks). i think 1.6 is about as far as i'm willing to risk it. on the other hand, if the chips in the 1.25ghz stock machines are the same, just with the resistors set at 167 fsb instead of 133, i'd change it to 167 in a heartbeat.
Russ

wowsa... if my quick math is on, that would plop you right down at 2.0. problem with that though, is our ram only runs at 133 mhz, so you'd need some different ram...

mikeyredk
Aug 16, 2004, 07:57 PM
couldn't you move to 167 on a lower cpu speed such as 1 gigz?

OziMac
Aug 16, 2004, 08:52 PM
Werneru - what kind of Xbench scores are you getting at 1.6GHz?

wernerru
Aug 16, 2004, 11:40 PM
Werneru - what kind of Xbench scores are you getting at 1.6GHz?
130's-140's. it's on their comparison site under DaMac. processor speed alone i get in the 190s

wernerru
Aug 16, 2004, 11:41 PM
couldn't you move to 167 on a lower cpu speed such as 1 gigz?
yeah, that's how they made the 1.25ghz stocks.
edit-and gave it another 256k L2 cache, which is why the xbench scores on the 1.25's are rather good.

wernerru
Aug 16, 2004, 11:43 PM
wowsa... if my quick math is on, that would plop you right down at 2.0. problem with that though, is our ram only runs at 133 mhz, so you'd need some different ram...
that and i don't know where the FSB jumpers are :confused: and what their settings would need to be :mad:

OziMac
Aug 16, 2004, 11:44 PM
Sorry for the ignorance, but how did you up the L2 cache?

[EDIT] Sorry, I get it now - Apple doubled the L2 cache, not you. lol ;)

wernerru
Aug 17, 2004, 12:04 AM
Sorry for the ignorance, but how did you up the L2 cache?
no ignorance at all my friend, i should have worded it better. Apple increased the L2 cache from 256k on the 800 and 1ghz stock machines, to 512k on the 1.25's. but considering from the processor standpoint, i'm almost hitting a 200 in xbench, i think i'm happy with the 1.6 at 133fsb. changing the fsb jumpers, with my luck, would kill my computer, plus i would have to change the cooling system. and doing another solder job to jump from 12x to 13x multiplier, in my eyes, isn't worth the risk of killing it for another 133mhz :)
edit- ha, you must have just done your edit, so i'll do mine now :D

SEN
Aug 18, 2004, 12:42 PM
Hello :)

Long time follower of this thread, first time poster.

Inspired by leo, I did a HD mod on my 1ghz eMac and everything went wonderfully - now running 120gig. The take-apart and re-assembly was enough to make me comfortable to do it again, complex in progress, but incredibly simple in retrospect :)

The question of 'to clock or not to clock' has been going over in my mind since leo first did the mod - and now I think I'm up for it.

I have one simple question (I think this may have been mentioned before, but I can't seem to find or recall where/if it was mentioned) - after changing the multiplier configuration, do you need to press the PMU reset switch?

This is all off the top of my head - I don't remember if I dreamt it and read it. I have a feeling something about this is mentioned in the eMac disassembly docs, something about battery life going from years down to days (if not done, or done too much)*.

Can anyone clear this up?

Thanks

PS. Eager to hear more about the 1.6+ stability etc.

* Chief Wiggum: "And if your nose bleeds, you're picking it too much.. or.. not enough."

mikeyredk
Aug 18, 2004, 08:02 PM
just one question i was looking at the apple take apart guide *don't ask how i got it :rolleyes: *

how did you discharge the tube display? if you didn't how did you get at the logic board?

SEN
Aug 18, 2004, 08:49 PM
I didn't discharge the CRT.

Keep your Mac shut down for a while* and hopefully** the voltages will dissipate.

I shut mine down for about an hour and made sure I didn't go near anything monitor-wise - doesn't sound so professional but I am (and the eMac are) still okay :)

* I've heard different reports of how long you should leave it shut down and unplugged. ** If my memory serves me correctly, Leo says something along the lines of "switch it off for 30 minutes or so to let the high voltages dissipate" and I've read in other places that you should shut down for 24 hours.

wernerru
Aug 19, 2004, 02:45 PM
just one question i was looking at the apple take apart guide *don't ask how i got it :rolleyes: *

how did you discharge the tube display? if you didn't how did you get at the logic board?
i didn't discharge the CRT either, and i completely forgot to wait. Some CRT's, like TV's, can hold the charge for 20years+. It was really easy to get to the jumpers too, just take the optical drive out, and they're right under.

As for the other guy asking about the stability of my eMac running at 1.6, it's been great. Most apps open close to instantly, simple things like textedit and terminal are up before you can even let go of the button. I still want to take the fsb to 167, but then i'd be at 2.0ghz, and have to buy new memory, and probably a better cooling system

mikeyredk
Aug 19, 2004, 03:09 PM
I don't think there is such a thing as pc167 ram. the next step up is ddr ram.

Mord
Aug 19, 2004, 03:12 PM
and ddr ram dont fit the emac slots, just pop some ram sinks on the dimms

wernerru
Aug 19, 2004, 03:14 PM
and ddr ram dont fit the emac slots, just pop some ram sinks on the dimms
problem is, is that the pc133 won't run in the 167 environment. computer powers on, beeps a few times saying there's no working memory, and then powers off.

Mord
Aug 19, 2004, 03:16 PM
there may be a way to edit the firmware to disable the ram check

SEN
Aug 20, 2004, 01:55 AM
the stability of my eMac running at 1.6, it's been great. Most apps open close to instantly, simple things like textedit and terminal are up before you can even let go of the button.

Very cool to hear! :)

How long do you keep it running and running at 100% CPU usage?

Basically my eMac never stops working - I never shut it down and I never let it sleep ( in fact I make it work while I sleep :) ). This is my only concern. I think Leo said he has kept his running for over half a year and he hasn't had any problems.

Did you press the PMU switch after touching the motherboard?

wernerru
Aug 20, 2004, 01:53 PM
Very cool to hear! :)

How long do you keep it running and running at 100% CPU usage?

Did you press the PMU switch after touching the motherboard?
It's been up 24/7 since i did the clock, and the first few days i had it running at 100% in a warm room. The temperature coming out of the fan hardly rose since the clock, i'm still considering putting a speed controller on it so it'll be quieter. I didn't push the PMU switch, but when i booted it said my time and date were off, so i shut down and pushed it, for fear of killing the battery life down to a few days. Other than that, no hitches

OziMac
Aug 22, 2004, 05:01 AM
Sorry again - but what's the PMU and where/why do you swicth it?

wernerru
Aug 22, 2004, 11:49 AM
Sorry again - but what's the PMU and where/why do you swicth it?
You can see/press the PMU reset button under the memory access door on the bottom. When you have it apart to do the clock, it's on the upper right, above the optical drive mounting. After you get done doing whatever you're going to do on the mobo, just press it, and then put it back together. just don't press it twice in a row!

SEN
Aug 22, 2004, 12:16 PM
Phew!

What a tense, emotional ride that was ;)

Just did the clock! :p

Maybe a little greedy to start with, but I was inspired by wernerru - not greedy enough to go with 1.6ghz mind you - but I tried a 11x clock, taking me from 1ghz to 1.467ghz. (Actually I was contemplating a 2ghz clock by prizing off one jumper, but that seemed too much ;)). Going to 1.467 was going to be an easy mod, prizing off two jumpers to make a -++--- configuration.

Well, after the initial excitement, it didn't boot - and to increase the stress levels it beeped at me 4 or 5 times (not good, according to the service manuals).

Next I tried making one connection to take it to 1.4ghz. Still no boot. I was convinced I had fried something. I checked my shabby soldering and thought I had some "hair-line" connections happening. Either that or my heavy-handed prizing off of jumpers had severed something on the motherboard. So I stupidly started scratching and resoldering. Nothing.

Then, prized off another jumper to make it 1.33ghz. And bam! A picture!
Only thing was that it was a little unstable - I started trying to do things like convert video and got some really bad artifacts happening. The whole computer would lock up after 5-10 mins, not even under heavy load.

So, I pulled it back to 1.2 and everything worked fine. Then soldered one jumper to make it 1.27 - and here i am. I think this is the peak for my machine. The sad situation is that I could have saved myself a lot of inconvenience by prizing off the other two jumpers in the beginning (taking me straight to 1.27 using the surface mounted resistors, not solder). Oh well, I would have been living in perpetual wondrance, itching to know if I could run it faster.

Hasn't crashed yet - I thought I had some funny business going on, but I think it was down to me launching every single application I could find (all at once!). I'm happy with this speed :)

Leo, you are a king among men

SEN
Aug 22, 2004, 12:25 PM
New sig :)

I should also add....

I didn't believe what people were saying about the size of the jumpers. Although they look kinda small, Leo's pictures of them compared to a USB connector don't seem convey the size until you actually see them in real life :p

SEN
Aug 23, 2004, 02:31 AM
Updated sig. ;)

Well... despite the stability and the machine working fine at 1.27ghz, I noticed that whilst doing some tests some odd things occurred.

I tried to test performance with DiVA (http://diva.3ivx.com) and 3ivx (http://www.3ivx.com) converting MPEG video to QuickTime and at 1.27ghz I was getting strange artifacts occasionally.

They were infrequent enough to be disregardable, but they were definitely the result of the OC, not the codec. They looked very similar to the artifacts experienced at 1.33ghz (random blue areas, maybe a few pixels wide), but were less in count.

Pulling the machine back to 1.2ghz seems to have fixed it. Being a quality nazi, this was an important fix :p

lbodnar
Aug 23, 2004, 10:04 AM
Pulling the machine back to 1.2ghz seems to have fixed it.:p
REM, what processor revision do you have (System profiler -> CPU type)?
I believe this will indicate approximate period of its manufacturing.

SEN
Aug 23, 2004, 10:40 AM
More stats than you need to know ;)

Machine Model: eMac
CPU Type: PowerPC G4 (3.3)
Number Of CPUs: 1
CPU Speed: 1.2 GHz
L2 Cache (per CPU): 256 KB
Memory: 1 GB
Bus Speed: 133 MHz
Boot ROM Version: 4.6.4f1

eMac:~ sen$ machine
ppc7450

wernerru
Aug 23, 2004, 02:12 PM
REM, what processor revision do you have (System profiler -> CPU type)?
I believe this will indicate approximate period of its manufacturing.
i'm starting to think i might have just gotten lucky, either with the machine manufacture date, or just a random set of components, but i've been running nonstop at 1.6ghz, no problem, with teh same hardware reports as SEN.

OziMac
Aug 24, 2004, 08:24 AM
Well, I did it.

Like SEN, didn't have the guts to do a werneru and go to 1.6GHz for fear of throwing out the baby with the bath water. I wanted to ensure that my eMac would stay stable and not produce artefacts in video compression, which is half the point of the overclock.

So, I went straight for the 1.2GHz +---- configuration (I previously had +++-+ for 1GHz). Didn't use an xacto knife - instead used some metal tweezers. Had pretty much the same effect - I was only able to retrieve one of the jumpers. Am going to have to learn to solder if I am to change the settings again though. And didn't press the PMU though my date/time has not reset so that's okay, right?

However, while I did this I also upped my memory from 512MB to 1GB. Yet my XBenches are still around 110 - in fact, slightly lower than before! Any ideas?

Also, anyone know where the 'Third generation' (1GHz) eMac take apart guide is? I can't find my copy. I'm trying to work out how to get to the Hard drive to upgrade it, and Leo's guide is for the second generation eMacs. [EDIT] Found them on Leo's site.

Thanks again for your advice guys, has been very interesting.

SEN
Aug 24, 2004, 09:10 AM
Run XBench after a fresh boot.

After my 1.2 clock I am getting about 118-121 (on a good day). I noticed that things such as the Disk Test would let down my overall XBench score (maybe my HD is a little cluttered up at the moment - random read/write do give fluctuating scores I've noticed).

In fact, right now I accidently clicked my mouse during an XBench test and I got 101 (plus I have a few apps open)

What do you get overall for your CPU Test and Memory Test?
Here's my results (post [and prior] overclock):

CPU Test 143.04 (compared to 120.45 @ 1 ghz)
GCD Loop 137.55 5.37 Mops/sec
Floating Point Basic 143.82 520.11 Mflop/sec
AltiVec Basic 146.54 4.26 Gflop/sec
vecLib FFT 144.70 2.25 Gflop/sec
Floating Point Library 142.89 5.72 Mops/sec

Memory Test 95.06 (compared to 95.29 @ 1ghz)
System 100.80
Allocate 774.95 505.50 Kalloc/sec
Fill 97.51 776.21 MB/sec
Copy 54.90 274.49 MB/sec
Stream 89.94
Copy 87.86 642.23 MB/sec [altivec]
Scale 86.97 641.84 MB/sec [altivec]
Add 89.94 575.62 MB/sec [altivec]
Triad 95.47 583.30 MB/sec [altivec]

OziMac, I'm in Australia too - when did you buy your eMac?

wernerru
Aug 24, 2004, 10:04 AM
CPU Test 190.69
GCD Loop 182.12 7.11 Mops/sec
Floating Point Basic 197.81 715.33 Mflop/sec
AltiVec Basic 196.07 5.70 Gflop/sec
vecLib FFT 186.54 2.90 Gflop/sec
Floating Point Library 191.82 7.68 Mops/sec

sushi
Aug 24, 2004, 10:31 AM
Tomahawk is an awesome plane, I just got my license in a Warrior/Archer.
Congrats on the license!

I flew the 140 (Cruiser I think), Warrior and Archer. Good airplanes. Last a long time! I got my license almost 30 years ago. Damn!

Anyhow, congrats again!

Sushi

lbodnar
Aug 24, 2004, 11:15 AM
Congrats on the license!

I flew the 140 (Cruiser I think), Warrior and Archer. Good airplanes. Last a long time! I got my license almost 30 years ago. Damn!

Anyhow, congrats again!

Sushi

You bet! Local club sold all Tomahawks :mad: however they had like 6000+ airframe hours. That's increadible mileage for the small plane. And most of those are student hours (i.e. x2 ?) They also seemed to land themselves - I just can't do greasers in Cessnas. Maybe I am trying impossible?

vga4life
Aug 24, 2004, 01:30 PM
Has anyone yet cracked a 1.25GHz emac to see if a similar hack is possible?

The only 2004-model emac mod I've yet seen is someone adding a fan controller, and that page was light on pictures of the actual mainboard.

My emac is still under warranty, so I'm not anxious to crack it open just yet.

-vga4life

sushi
Aug 24, 2004, 10:26 PM
You bet! Local club sold all Tomahawks :mad: however they had like 6000+ airframe hours. That's increadible mileage for the small plane. And most of those are student hours (i.e. x2 ?) They also seemed to land themselves - I just can't do greasers in Cessnas. Maybe I am trying impossible?
Yeah, that is a lot of student hours for sure.

Flew a Tomahawk once. Not a bad little plane.

Reference greasers, I assume that you are referencing a landing in which you just hear the wheels spin without any noticable contact with the runway.

If so, then to me doing a greaser in a Cessna is much easier than a Piper product. Landing in a strong crosswind is another situation. In this case a Piper product is much better than a Cessna.

The key is to find the air bubble when you are near the ruway and hold onto it as you land. BTW, never learned about this air bubble, or cushion of air as us rotor heads call it, until I learned to fly helicopters.

Another thing that can help, is practicing slow flight where you get it to the edge of the stall, then power through it and continue to fly.

Have fun flying! :D

Sushi

OziMac
Aug 25, 2004, 07:33 PM
SEN - I bought mine in April of this year.

Xbenches are not back up to 120-125. I am getting about 143 on the CPU test - if only it were possible to put in a graphics card! But I'm more than happy.

You are damn lucky with yours werneru, and thanks for the inspiration - I wouldn't have been game for it without your report.

And also thanks for the report regarding stability, SEN. Otherwise I may have been overzealous and tried for 1.6Ghz only to find that I would have to learn soldering fast in order to revive my eMac.

:)

SEN
Aug 26, 2004, 08:35 AM
Wernerru, those stats are amazing - don't touch a thing ;) That seems to be better than the G5 1.6 we've got at work!

SEN - I bought mine in April of this year.

Ahhh, I bought mine around June last year. Yours must have been the last of the line before the 1.25 models ( at least you've claimed back some of those lost mhz :p )

Xbenches are not back up to 120-125. I am getting about 143 on the CPU test - if only it were possible to put in a graphics card! But I'm more than happy.

Yeah, 143 is what I'm getting for the CPU, I guess that's what's important - XBench is great because you can diagnose "specific problem areas in performance" ( or so I'm brainwashed to believe - http://www.xbench.com/ ;) ) - so something else is pulling your total score back quite a bit.

And also thanks for the report regarding stability, SEN.
You're welcome OziMac :) Glad to have given something back to this thread :p

wernerru
Aug 26, 2004, 09:00 AM
Wernerru, those stats are amazing - don't touch a thing ;) That seems to be better than the G5 1.6 we've got at work!
Yeah, it's running great, i've been running folding@home non-stop since saturday, and it's hardly any warmer. I'm just glad my reckless overclock managed to inspire some more eMac owners into getting back the real speed these things should have. As for not touching it... i don't plan on it! only one other person i've heard of overclocked it to 1.6, and they took it down to 1.33 because of artifacts after a few days.

OziMac
Aug 26, 2004, 09:10 AM
I meant to say 'now' up to 120-125. Nothing holding it back except the 256k cache!

lbodnar
Aug 26, 2004, 11:30 AM
The key is to find the air bubble when you are near the ruway and hold onto it as you land. BTW, never learned about this air bubble, or cushion of air as us rotor heads call it, until I learned to fly helicopters.

Low-wings get into ground effect layer much earlier during the flare and end-up having a better cushioning than those high-wings. So how about a chopper with the main underneath you?! :D

Sorry for complete OT!

Windowlicker
Aug 26, 2004, 12:01 PM
nice one! btw after having everything done, wan't it such a pain in the ass to get the shell back on it's place so that you got the screws back in?!

I've opened a couple of emacs at work.. opening is easy, but closing it is much harder.

anyway good job with the manual and your little experiment.

wernerru
Aug 28, 2004, 03:39 PM
another update - tried to take it to 2ghz, it worked for about a minute after full boot, and the artifacts got unbearable. BUT, it booted! it ran long enough for me to get an xbench CPU score of 245.7!!!

mikeyredk
Aug 28, 2004, 10:53 PM
sweet even for a minute

lemmy
Aug 30, 2004, 01:00 PM
I have read all this with interest and will attempt next time i get the urge,
however there is one thing that puzzles me.

the emac resistor configuration seems easy to translate in to + - relating to with or without resistors as there's only 5 resistors, the imac has a double bank of resistors (10 in total) and there's not been any (idiots) explanation as to where to place the connections/removals, could someone enlighten me please.

this got close
Inspired by lbodnar's article, Numbski's link and discussion on this thread, I manage to overclock my iMac FP 17 inches 1G Hz to 1.27G Hz (via changing CPU's multiplier from 7.5x to 9.5x under FSB 133MHz). Here is my iMac's mainboard picture with detail location of resistor bank.

R374 R376 R378 R379 R382 ---> left column resistors on picture
7.5x + - - - -
8x - - + + -
8.5x - + + - -
9x + + + - +
9.5x + + + - -
10x - + - + +

+ : with resistor
- : without resistor

For the right column resistors R375, R377, R380, R381, R383 it is simply "inverse" of left column, i.e. For each row the resistor located either on left side or on right side.

Put in another way:
===================
According 7455 datasheet page 47,48 : CPU's Bus-to-Core Multiplier table. For example, if you want 7.5x the PLL_CFG[0:4] column is "00010" with order "Bit 5, Bit 4, Bit 3, Bit 2, Bit 1" than only "Bit 2" set to "1", That mean R374 should mount a resistor (so R375 need not mount resistor) ....

R374,R375 ---> Bit 2
R376,R377 ---> Bit 3
R378,R380 ---> Bit 4
R379,R381 ---> Bit 5
R382,R383 ---> Bit 1

but I'm still a bit puzzled (do i have to change just the left column, and/or make the right column a mirror image?, or just remove all the resistors in right column and an make the changes to the left column?)

lemmy
Aug 30, 2004, 05:28 PM
resistors are in this order on the logic-board
R374,R375 ---> 2
R376,R377 ---> 3
R378,R380 ---> 4
R379,R381 ---> 5
R382,R383 ---> 1

and read in reverse ie 5,4,3,2,1 of the numbers in the Motorola PDF file


Explanation
http://homepage.ntlworld.com/lemmingsdial/resistors.jpg

If my method is correct, read the left column of resistors from top to bottom (R374,R376,R378,R379,R382)

x5.5 = 1 0 0 1 0
x6 = 1 0 1 1 0
x6.5 = 1 0 1 0 0
x7 = 0 1 0 0 0
x7.5 = 1 0 0 0 0
x8 = 0 0 1 1 0
x8.5 = 0 1 1 0 0
x9 = 1 1 1 0 1
x9.5 = 1 1 1 0 0
x10 = 0 1 0 1 1
x10.5= 0 0 0 1 1
x11 = 1 0 0 1 1
x11.5= 0 0 0 0 0
x12 = 1 1 0 1 1

Numbski
Sep 1, 2004, 12:58 PM
You know, I'm sitting here plotting on the new iMac, what I can do to get some more horsepower out of it, even have a link to an uncompressed tiff image of the logic board, but wouldn't you know it? The clock chip appears to be covered by the aluminum 'G5'?

Ugh! You're killing me here people! You mean I have to actually buy the thing and crack it open before I can know whether or not this is an underclocked chip in these new iMac's? (Although in my heart of hearts I know it is....) :D

Numbski
Sep 1, 2004, 01:00 PM
Oh, just as a head's up since this is getting to be quite the long thread:

My blog (http://www.numbski.net/journal/imac_hack)

lbodnar
Sep 1, 2004, 01:39 PM
You know, I'm sitting here plotting on the new iMac, what I can do to get some more horsepower out of it, even have a link to an uncompressed tiff image of the logic board, but wouldn't you know it? The clock chip appears to be covered by the aluminum 'G5'?


I'll let them know it's in the wrong place :)

By the way Apple says Proudly display the iMac G5 in any room of your house — it’s lightweight enough to move from your kitchen to the den or bedroom. A light Li-Ion battery that keeps it up for 10-15 minutes would be nice for moving it around or as a simple UPS to save it from power drops.

Numbski
Sep 1, 2004, 02:06 PM
Of course I don't have the original tif file handy, but Leo...you have a habit of doing things to make me scream here. :eek: I can't tell from your image if all of the jumper points for the cpu clock are at that location, or if it's a pointer to elsewhere.

Would help if we could see the actual chip. See what multipliers and FSB speeds are available for starters.

lbodnar
Sep 1, 2004, 02:24 PM
I can't tell from your image if all of the jumper points for the cpu clock are at that location, or if it's a pointer to elsewhere.

Would help if we could see the actual chip. See what multipliers and FSB speeds are available for starters.

:) Below is a verbatim quote from the original tiff. There seems to be at least two jumpers at each position so you have at least 4 CPU CLK and 4 MB CLK [memory bus?] options. Plenty to start with!

Numbski
Sep 1, 2004, 02:33 PM
Thanks man. Unfortunately, until someone opens one up, and pulls off that cover, we can't see what the clock chip is to see what those points control. Perhaps I can google around a bit...see if anyone has an image of the current G5 cpus/clock chips. If we have a very similar number of banks for the cpu/fsb, then it's likely to be the same.

On a side note, the 20" iMac weighs about 25lb!

Display it in any room. Just don't hurt your back. ;) Adding a batter would likely put that number over 30lb.

Not TOO heavy I guess.

Numbski
Sep 1, 2004, 06:09 PM
Okay, here's the rest of the info that I've managed to dig up today:

There are two FSB speeds that are being sold right now, 533 and 600 (man that's a step up!!!!), and two CPU speeds being sold: 1.6 and 1.8 Ghz.

The 1.6 is a 3x multiplier with 533 FSB.

The two 1.8's are 3x multiplier with 600 FSB.

The Powermac cousins have clock speeds of 1.8, 2, and 2.5.

The 1.8 is a 2x multiplier with 900 FSB (!!!)

The 2 is a 2x multiplier with 1000 FSB (!!!!)

The 2.5 is a 2x multiplier with 1250 FSB(!!!!!)

Given that you though there were 4 positions for each of these, I wonder what the those options are? So far we've only seen 2 multipliers, but 5 FSB options. A kick from 600 to 900 would be a 50% speed boost all by itself.

This just ain't right.