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grabberslasher
Apr 23, 2003, 11:00 AM
I just software overclocked my Rev A. G4 400 to 533MHz!

Well, sort of. Following instructions on XLR8yourmac.com I went into the Open Firmware prompt and typed in a few commands to increase my system bus from 100MHz to 133Mhz.

Suddenly on restarting my G4 it happily proclaims to be a G4 533MHz in About this Mac and Apple System Profiler (10.2.5).

I was in a state of shock at first - over 25%. The XLR8yourmac article stated that it probably wont work over 50MHz but I have been running it at that speed for a few weeks now with less than 1š increase in heat.

Has anyone got any comments/suggestions (apart from EVACUATE!).

For those interested - these are the commands I typed (from xlr8):


"How to edit and store the NVRAMRC for 133MHz bus

(1) Boot by holding down "Cmd" + "Opt" + "O" + "F" keys to enter the OpenFirmware terminal.

(2) Enter the NVRAMRC editor. (<return> shows you should type "return" key)
nvedit <return>

(3) Type following script exactly (including spaces).


" /" select-dev <return>
7efdc44 " clock-frequency" get-my-property 2drop ! <return>
" /cpus/PowerPC,G4@0" select-dev <return>
1fca0554 " clock-frequency" get-my-property 2drop ! <return>
7efdc44 " bus-frequency" get-my-property 2drop ! <return>
1fbf711 " timebase-frequency" get-my-property 2drop !


(4) Type "Cntl" + "C" to exit NVRAMRC editor.

(5) Save the script
nvstore <return>

(6) To enable the NVRAMRC, type this command.
setenv use-nvramrc? true <return>

(7) Reboot with new timebase constant.
reset-all <return>

"



cc bcc
Apr 23, 2003, 11:33 AM
Can you provide a link to the article? I'd like to know of a way back when things go wrong. It's a cool hack!

grabberslasher
Apr 23, 2003, 11:38 AM
See the last step of the post:

"setenv use-nvramrc? true"

To undo any changes just type:
"setenv nvramrc? false"

All it does is tells the Open Firmware to run a setting script at startup.

To completely reset it just zap your PRAM -
Hold command-alt-p-r at startup.

Wait a minute while I get the URL.

grabberslasher
Apr 23, 2003, 11:39 AM
http://www.xlr8yourmac.com/G4ZONE/sawtooth/SawtoothCPUdesign.html

There you go.

jethroted
Apr 23, 2003, 12:03 PM
They say it does not work for OSX though.:( That sucks.

grabberslasher
Apr 23, 2003, 12:32 PM
Of course it runs in OS X - as I said, I am using 10.2.5. It doesn't run on OS X prior to 10.1.1 (I think) - but who in their right mind would use such an early version of X at this stage?

Don't flame me for saying that!
It works perfectly - especially with it's new Geforce3Ti 64Mb graphics card and extra RAM - 384Mb.

The article also states that it will only read from two RAM slots and you must have 133MHz Ram to use it.

I have only the original RAM with my machine and all 4 slots are fully used after the hack.

grabberslasher
Apr 23, 2003, 12:35 PM
If you want screenshots/photos to prove it I can show you. The serial number on the back of the machine will prove that it was a 400MHz machine.

jethroted
Apr 23, 2003, 12:40 PM
Originally posted by grabberslasher
Of course it runs in OS X - as I said, I am using 10.2.5. It doesn't run on OS X prior to 10.1.1 (I think) - but who in their right mind would use such an early version of X at this stage?

Don't flame me for saying that!
It works perfectly - especially with it's new Geforce3Ti 64Mb graphics card and extra RAM - 384Mb.

The article also states that it will only read from two RAM slots and you must have 133MHz Ram to use it.

I have only the original RAM with my machine and all 4 slots are fully used after the hack.

Sorry, I misread that part.

grabberslasher
Apr 23, 2003, 12:54 PM
Of the 120+ people who have viewed this thread do any others have any comments?


Say something...

gotohamish
Apr 23, 2003, 01:00 PM
Originally posted by grabberslasher
Of the 120+ people who have viewed this thread do any others have any comments?


Say something...

Yeah, I do.

I have a Sawtooth G4 500, processor upgraded to 1.3Ghz, with the processor jumpers set for a 100Htz bus, anyone know how applying this hack would affect that?

grabberslasher
Apr 23, 2003, 01:30 PM
I could tell you if I knew your multiplier (for your upgrade card).

Your original multiplier is 5 (5x100Mhz) so your upgrade card must be 13(?!). I'm not sure, but multiply 133MHz by 13 for your end result.

1.729 GHz!

But I doubt that the hack will apply to your upgrade card. More likely it will only overclock your 500MHz (to 665). There's no harm in trying - I don't think a simple hack such as this can damage your computer. All it is is basically a startup setting.

True speed increase though.

Pentium Killer
Apr 23, 2003, 01:33 PM
I tried it and nothing happenened.Igot a G4 Sawtooth,too.Donīt I have to press return after

1fbf711 " timebase-frequency" get-my-property 2drop !

And what does type "Cntl"+"C" mean?
Directly after the line I quoted before?
So I have to type "Cntl" "C"?
What is this + for?Do I have to type it too?My god,this is not that easy
;)

Pentium Killer
Apr 23, 2003, 01:43 PM
Anyway,#i give it a try again.

Pentium Killer
Apr 23, 2003, 02:06 PM
I tried again and nothing changed.Maybe I had some typos,I do not know.It is hard to see sometimes if I have to type space or not.

WannabeSQ
Apr 23, 2003, 02:33 PM
Originally posted by gotohamish
Yeah, I do.

I have a Sawtooth G4 500, processor upgraded to 1.3Ghz, with the processor jumpers set for a 100Htz bus, anyone know how applying this hack would affect that?

Well, this hack basically overclocks the bus to 133, so it might help the upgraded processor indirectly. You will have to change the multipliers on the Gigadesigns card to the 133mhz bus versions to get 1.33ghz. I bet it would help your performance. The only reason it "overclocks" the processor is the bus running faster. Most of the time when u overclock the bus you downclock the multiplier on the processor so you dont fry it.

I might try it on my sawtooth 500, I can't permanently break anything if it doesn't work right? and if I do, it would just be the processor right? I was planning on gettin a faster one anyway....

digitalgiant
Apr 23, 2003, 03:18 PM
Will this work on a 667 PB? My baby is starting to show its age.

grabberslasher
Apr 23, 2003, 03:19 PM
Cntrl C means press
the control button and c at the same time. Like command-c for copying.

Trust me, it does work.

Yes you must press return after each line. Spaces are also important.

ecino1
Apr 23, 2003, 03:54 PM
WOW. I just tried this on my AGP G4 400, and it worked!!! I attached a screen shot to prove it. It shows 133mhz bus and a machine speed of 533mhz. I cant tell if it is any faster so far. Is there a way to test this? Hey, other guy that did this, does yer machine seems faster? Let me know.

Nipsy
Apr 23, 2003, 03:54 PM
I tried the similar hack on my MDD 867, and the computer presented info of a faster bus, but the machine was not running any faster.

Do a pair of XBench tests to see if there is an actual difference going on.

ecino1
Apr 23, 2003, 04:12 PM
Sorry, here is the screen shot. I will do xbench now and compare the results.

me hate windows
Apr 23, 2003, 04:17 PM
i am still confused about the ram, would my pc100 still work?

ecino1
Apr 23, 2003, 04:26 PM
About the RAM, when i did the hack all 4 of my ram modules were recognized! Sadly, when i used xbench on the computer while the hack was applied my xbench score was only 46.24, which is lower than my original xbench test score of 50.03 taken just before applying the firmware hack!! I don;t understand why this would actually SLOW DOWN my machine, even if it just was displaying fake information. Well, it didnt seems to do any harm, and zapping the p-ram returned my system to normal. I guess others could give it a try and see if they get better results, but i doubt this actually does anything beneficial.

Hemingray
Apr 23, 2003, 04:50 PM
Originally posted by grabberslasher
I just software overclocked my Rev A. G4 400 to 533MHz!

Be careful... technically a "Rev A. G4 400" is the Yikes G4, not the Sawtooth.

Fortunately I know that this would not work on my Yikes G4 (as the Yikes is overclocked by changing the jumpers on the mobo), but if someone else with a Yikes G4 came along and tried this, it could possibly screw up their computer. (Not sure about that, but messing with OF is never a light matter...)

Anyways, I would suggest clarifying that by "Rev A." you mean Sawtooth.

grabberslasher
Apr 24, 2003, 03:26 AM
I don't see why the 350MHz G4 (Yikes) would be classed as a Rev A. - it came out at the same time as the Sawtooth model.

Let's just say "early Sawtooth G4s" (originally 400-450MHz after Apple reduced the speeds of the lineup).

In other words - if you have a Sawtooth G4 with a green glowing power button you can do this.

It is untested on later G4s (white glowing power button).

I tried the X bench tests and got a score of about 52.4 on mine (compared to about 49). I don't see why yours might have slowed down. Interesting.

grabberslasher
Apr 24, 2003, 03:29 AM
I just checked my G4 - one of my newer RAM sticks is actually 133MHz RAM. Maybe it only speeds up your computer if you have faster RAM. I'll try taking out the stick and checking X Bench.

grabberslasher
Apr 24, 2003, 03:35 AM
Yeah, the Ram does help but the machine was still faster with the OF Hack. What graphics card do you have, ecino1? That might account for the Xbench results. Also, a faster hard drive will help a lot in the read/write tests

Also what extra kernel extensions and other stuff have you installed on your System.

gotohamish
Apr 24, 2003, 05:18 AM
Originally posted by grabberslasher
I could tell you if I knew your multiplier (for your upgrade card).

Your original multiplier is 5 (5x100Mhz) so your upgrade card must be 13(?!). I'm not sure, but multiply 133MHz by 13 for your end result.

1.729 GHz!

But I doubt that the hack will apply to your upgrade card. More likely it will only overclock your 500MHz (to 665). There's no harm in trying - I don't think a simple hack such as this can damage your computer. All it is is basically a startup setting.

True speed increase though.

I have a Gigadesigns 1.25Ghtz upgrade card, with the processor jumpers moved slightly so it correctly registers in ASP/About... as 1.3Ghtz (both OSX/9). They have jumper setting on xlr8yourmac and on gigadesign.com - do you think I could still apply this hack as there are separate jumpers on the upgrade card to use a 133Hz bus.

I'd hugely appreciate everyone's help with this.

Check out my old thread for more details about my machine...http://forums.macrumors.com/showthread.php?s=&threadid=23975&highlight=1.3

davegoody
Apr 24, 2003, 05:25 AM
Whey Hey !!!! - Just upgraded my PBG4 400Ti to 1 Gig

How I hear you ask . . . . . . . . . . . .

Really simple. . . . . . . .

Bought a new one ! ;)

Seriously though, using PC100 RAM will probably stop the hack from working as MOST PC100 RAM will not work correctly (or in some cases at all) at speeds of 133. If possible change it all for PC133 then re-test speed - will be interesting to see if it works.

Keep Smiling

Pallish
Apr 24, 2003, 07:10 AM
Does anyone know if this hack works with Quicksilvers?

Currently running a 733 Mhz.. want it to be faster =)

gotohamish
Apr 24, 2003, 08:43 AM
Originally posted by Pallish
want it to be faster =)

Ahh, the eternal statement!

Hemingray
Apr 24, 2003, 11:00 AM
Originally posted by grabberslasher
I don't see why the 350MHz G4 (Yikes) would be classed as a Rev A. - it came out at the same time as the Sawtooth model.

Let's just say "early Sawtooth G4s" (originally 400-450MHz after Apple reduced the speeds of the lineup).

Not quite. I said the "Rev A. G4 400" was a Yikes model. When the G4s were introduced in August 1999, the 400MHz model was a Yikes, and only the 450MHz model was a Sawtooth. The 400MHz Sawtooth didn't replace the Yikes model until October 1999.

So technically speaking, a Rev. A G4 400 is a Yikes and not a Sawtooth. Anyone confused yet? :D

Hemingray
Apr 24, 2003, 11:16 AM
Originally posted by Pallish
Does anyone know if this hack works with Quicksilvers?

Currently running a 733 Mhz.. want it to be faster =)

Nope. The QS is a different beast.

You may find the following pages helpful:

http://www.lostboi.com/tutorials/overclockg4.html
http://www.bekkoame.ne.jp/~t-imai/g4de1.html (English page)
http://www.bekkoame.ne.jp/~t-imai/g4dj1.html (Japanese page w/ more pictures)

Overclocking the QS requires physically altering the motherboard. Not for the faint of heart.

jayscheuerle
Apr 24, 2003, 11:25 AM
Originally posted by grabberslasher
If you want screenshots/photos to prove it I can show you. The serial number on the back of the machine will prove that it was a 400MHz machine.

I don't mean to insult your personal integrity, but screenshots or photos offer no proof in this digital age... - j

MrMacMan
Apr 24, 2003, 12:45 PM
Originally posted by jayscheuerle
I don't mean to insult your personal integrity, but screenshots or photos offer no proof in this digital age... - j

erg, that is lame.

FelixDerKater
Apr 24, 2003, 01:37 PM
I have two PC133 SODIMMs in by TiBook 500. Would the bus change work on the laptop as well? My concern would be overheating beyond the already high temperatures of the system in its stock configuration.

grabberslasher
Apr 24, 2003, 03:16 PM
Originally posted by Hemingray
Not quite. I said the "Rev A. G4 400" was a Yikes model. When the G4s were introduced in August 1999, the 400MHz model was a Yikes, and only the 450MHz model was a Sawtooth. The 400MHz Sawtooth didn't replace the Yikes model until October 1999.

So technically speaking, a Rev. A G4 400 is a Yikes and not a Sawtooth. Anyone confused yet? :D

Actually - if you remember correctly - Apple couldn't get enough 500MHz processors off Motorola at the launch of the G4 so it downclocked the whole range by 50MHz. The Yikes model was originally 350MHz and my model was one up - a Sawtooth 400MHz.

Bought it a few weeks after the launch.

So techically my machine was a "Revision A" machine.

Henriok
Apr 24, 2003, 04:29 PM
I can confirm that it works on PowerBook G4 rev.A.
I have just overclocked my TiBook/400 to a much "snappier" ;) TiBook/533.

I was a bit worried if my RAM would hold for the 133 MHz bus, but it did, and now I'm just waiting for the fan to kick in.. It havn't done that yet. T +33 mins and counting.

Thanks a bunch! This really made my day! A 33% faster machine after just 5 mins of haking!

gotohamish
Apr 24, 2003, 04:47 PM
Applied the hack to my 1.3Ghtz machine, and it reported 1.3Ghtz at 133Hz - but Xbench results were slower, expecuially in processors tests, so I've changed it back...

Hamish

ecino1
Apr 24, 2003, 05:44 PM
Originally posted by Henriok
I can confirm that it works on PowerBook G4 rev.A.
I have just overclocked my TiBook/400 to a much "snappier" ;) TiBook/533.

I was a bit worried if my RAM would hold for the 133 MHz bus, but it did, and now I'm just waiting for the fan to kick in.. It havn't done that yet. T +33 mins and counting.

Thanks a bunch! This really made my day! A 33% faster machine after just 5 mins of haking!

Did it actually make your machine faster? It actually gave me a lower xbench score, although i could not tell any speed difference on my G4 400. I am using the stock 16mb ATI rage card, with 896mb ram (all 133mhz), and a 7200RPM 80gig Maxtor Hd.

FelixDerKater
Apr 24, 2003, 05:51 PM
Well, the concept of a 165MHz speed increase sounds nice, but I don't have the money to replace my TiBook if it gets screwed, so I will leave it alone.

Pallish
Apr 24, 2003, 06:31 PM
hm..... wtf does "cntl" mean? it says to press "cntl" + "c"

is it control?

Mojo The Monkey
Apr 24, 2003, 07:36 PM
I tried this out on my 450 G4 Cube.

When I rebooted, ASP and About This Mac reported that I was running a 533 G4. This was not an expected result- with my 4.5 multiplier, I expected to get 600 MHz.

Casual usage revealed no obvious performance increase. I booted up from my Norton Utilities CD and tried out their System Info application. It reported no performance increase at all- if anything a minor speed decrease.

A reboot with a PRAM zap returned everything to the original state.

Hemingray
Apr 24, 2003, 07:44 PM
Originally posted by grabberslasher
Actually - if you remember correctly - Apple couldn't get enough 500MHz processors off Motorola at the launch of the G4 so it downclocked the whole range by 50MHz. The Yikes model was originally 350MHz and my model was one up - a Sawtooth 400MHz.

Bought it a few weeks after the launch.

So techically my machine was a "Revision A" machine.

I have a Yikes G4 400, and I ordered it a few days after the G4's launch. I'm merely stating that the first G4 to clock in at 400MHz was a Yikes, and not a Sawtooth. So, even using your argument, the claim of "I just software overclocked my Rev A. G4 400 to 533MHz!" could mean either a Yikes or a Sawtooth, and obviously this mod would only work on the Sawtooth, which was NOT the first 400MHz G4.

The Yikes G4 debuted at 400MHz on August 31, 1999. Then, on October 13, they downgraded the whole line 50MHz, as you said, and in stepped the 400MHz Sawtooth, making my Yikes G4 400 possibly the shortest lived Mac ever?? (Not sure about that.)

So, since the 400MHz Sawtooth was released AFTER the 400MHz Yikes, technically the 400MHz Sawtooth isn't a Rev. A. Not in the 400MHz's case. But for the rest of the G4 line? Yessir. I know this is turning into a big deal over minutiae, but it's a matter of principle. ;)

Urdam
Apr 24, 2003, 08:20 PM
Cool :)

TiBook
Apr 25, 2003, 07:16 AM
Originally posted by Pallish
hm..... wtf does "cntl" mean? it says to press "cntl" + "c"

is it control?
Japp, it is. ctrl + c would have been better to write.

I tried this at my computer. Hade a little problem in the beginning understand the text. But when i saw i did wrong from the start, i just did it right. But the funny thing is that my comuter were downclocked instead of overclocked. Computer:
Old: TiBook 550 Mhz @ 100 Mhz
New: TiBook 533 Mhz @ 133 Mhz

So, is there any way to change the multiplier for the processor, anyone know how to to that? ;)

gotohamish
Apr 25, 2003, 08:34 AM
I've done this successfully on a Ti500 (--> 533MHtz w/ 133 bus) and Xbench was slower, and on my O/C 1.3Ghtz Gigadesigns Sawtooth, and again, Xbench was slowers.

I've reset all mine now. Worth a try though...

benixau
Apr 25, 2003, 08:36 AM
sorry i am late:

the guy who did this to his MDD 867 - UNDO IT. To this on a DP system you must do it to both processors. Here:

if there is a space - TYPE IT
<return> means press the return key

" /" select-dev<return>
09ef21aa " clock-frequency" get-my-property 2drop !<return>
" /cpus/PowerPC,G4@0" select-dev<return>
09ef21aa " bus-frequency" get-my-property 2drop !<return>
408e4b46 " clock-frequency" get-my-property 2drop !<return>
09ee81bc " config-bus-frequency" get-my-property 2drop !<return>
027ba06f " timebase-frequency" get-my-property 2drop !<return>
" /cpus/PowerPC,G4@1" select-dev<return>
09ef21aa " bus-frequency" get-my-property 2drop !<return>
408e4b46 " clock-frequency" get-my-property 2drop !<return>
09ee81bc " config-bus-frequency" get-my-property 2drop !<return>
027ba06f " timebase-frequency" get-my-property 2drop !<return>

exit the nvram by pressing control-c on the keyboard then type:

nvstore<return>
setenv use-nvramrc? true<return>
reset-all<return>


MAKE SURE YOUR RAM IS FAST ENOUGH. This will set any machine with PC100 ram to needing PC133, PC2100 - PC2700, PC2700 - PC3200. If you have a 167 bus already i advise against this. i advise against this. This just undoes the slow down apple puts on in the factory. For a MD 867 system a real 1G will be a bit faster because the cache is not overclocked and is still running at 867 vs 1083 in a real 1G system

rugby
Apr 25, 2003, 10:16 AM
This is complete and utter crap. Show some benchmarks of dnet client running before and after the upgrade and then I'll believe you. I did this OF hack on my DP867 and it did nothing to real-life performance, only what it displayed.

Busting out the soldering gun is the ONLY way to overclock a G4.

Pallish
Apr 25, 2003, 10:30 AM
How come it works on MDD's but not on QS's??

rugby
Apr 25, 2003, 11:13 AM
Originally posted by Pallish
How come it works on MDD's but not on QS's??

I just said it didn't work on my DP867, which is a MDD.

It doesn't work on ANY G4 tower. Period. End of discussion.

shawnjackson
Apr 25, 2003, 12:15 PM
Originally posted by digitalgiant
Will this work on a 667 PB? My baby is starting to show its age.

sure it would work! except for the fact that your pb is already running on a 133mhz system bus...

Pallish
Apr 25, 2003, 12:28 PM
Originally posted by rugby
I just said it didn't work on my DP867, which is a MDD.

It doesn't work on ANY G4 tower. Period. End of discussion.


but what did it change? u said it says it changed altough no "real" performance was gained...

rugby
Apr 25, 2003, 01:36 PM
Apple's cpus are both software and hardware controlled. For lack of better explanation the OS more than likely asks OF what the speed is. OF will return the value of the cpu(s). The cpu's will run at that speed. Now, if you mess with OF and the OS asks it what speed are you running at and OF says the new speed, the OS will report the new speed but the hardware controls won't allow the cpu's to change to the new speed.

Basically OF is only fooling the OS and not the cpu's.

Henriok
Apr 27, 2003, 11:29 AM
Originally posted by ecino1
Did it actually make your machine faster? It made my machine quite a bit faster. I was actually amazed but the specs do state that my machine should be 33% faster.. let's see what the benchmarks say:

CocoaBench (tot - numbers - image - i/o)
400 MHz: 6.01 - 5.57 - 8.52 - 4.39
533 MHz: 7.46 - 7.60 - 10.28 - 4.35
faster: 24% - 36% - 20% - -1%

Xbench (Tot - CPU - Thread - Memory - Quartz - OpenGL - UI - Disk)
400 MHz: 41.24 - 32.54 - 29.09 - 55.57 - 55.15 - 46.47 - 51.18 - 36.50
533 MHz: 43.93 - 38.30 - 30.37 - 65.30 - 55.05 - 46.78 - 51.89 - 38.20
6.5% - 17.7% - 4.4% - 17.5% - -0.2% - 0.6% - 1.3% - 4.6%

pinneo
Apr 29, 2003, 12:18 PM
"The XLR8yourmac article stated that it probably wont work over 50MHz but I have been running it at that speed for a few weeks now with less than 1š increase in heat."

Is this the processor temperature? If so, how did you measure it? I've been looking for a temperature measurement utility for G4 processors like Thermograph was for G3s.

a1291762
Nov 20, 2003, 06:47 PM
I just bought a PowerLogix 1.4 Ghz G4 for my Sawtooth. Of course, right after installing it I found this info on bus overclocking. I'd like to try overclocking my bus (I've got PC133 RAM) but I don't want to fry my new CPU. I can test it out with my original 500Mhz G4 chip.

Basically, the problem with the new CPU is that it doesn't have jumpers so I don't know if I can change the multiplier. It's currently at 14 but I'd want only 10.5 to keep the same speed on a 133Mhz bus. Can I change this setting? Will it set itself automatically (I wish)? Will my chip fry if I run it at 1.8 Ghz?

Link

illumin8
Nov 20, 2003, 11:59 PM
Originally posted by benixau
MAKE SURE YOUR RAM IS FAST ENOUGH. This will set any machine with PC100 ram to needing PC133, PC2100 - PC2700, PC2700 - PC3200. If you have a 167 bus already i advise against this. i advise against this.
Would it be suicide to try this on my PowerBook 1.25 G4? If I got DDR 400 memory (PC3200), would it be able to take a 200 mhz. bus??? :confused: :D

Fukui
Nov 21, 2003, 12:46 AM
Originally posted by rugby
Apple's cpus are both software and hardware controlled. For lack of better explanation the OS more than likely asks OF what the speed is. OF will return the value of the cpu(s). The cpu's will run at that speed. Now, if you mess with OF and the OS asks it what speed are you running at and OF says the new speed, the OS will report the new speed but the hardware controls won't allow the cpu's to change to the new speed.

Basically OF is only fooling the OS and not the cpu's.
This is what is happening.
I did this to my G/F's iBook.
Its actually O/C'ed to 600Mhz and 100 Mhz bus up from 500 and 66Mhz.

I did Openfirmware to correct the OS X bad reporting of the speed...but I typed it wrong! Now it thinks its 100 Mhz. But the performance is actually faster then before.

XBench is probably slower because it probably divides the resuts by the clock to get a score...
http://homepage.mac.com/son_gohan/QenSan/pic2.jpg

wrc fan
Nov 21, 2003, 02:54 AM
Didn't you guys read the whole thread? It does not overclock your computer, except on the Sawtooth, if you try with another one all it does is change what your computer reports it as, but does not really change it's operating speed.

yamabushi
Nov 21, 2003, 03:00 AM
Originally posted by illumin8
Would it be suicide to try this on my PowerBook 1.25 G4? If I got DDR 400 memory (PC3200), would it be able to take a 200 mhz. bus??? :confused: :D
Maybe. 167MHz to 200MHz isn't that big of a jump. Your cpu could then run at 1.5GHz at the same 7.5X bus multiplier. This seems like a reasonable amount to overclock with good hardware components.

yamabushi
Nov 21, 2003, 03:02 AM
Originally posted by oaklandbum
Didn't you guys read the whole thread? It does not overclock your computer, except on the Sawtooth, if you try with another one all it does is change what your computer reports it as, but does not really change it's operating speed.
Well, we can try can't we? :)

profgaw101
Jan 21, 2004, 02:57 PM
I'm confused. The top of this thread says a G4 400 Rev A was used. Isn't that a yikes? Another post says only sawtooth will work. Which is it?

Ps - overclocked my yikes to 450 mhz using jumpers. anyone else do this?

Hemingray
Jan 21, 2004, 03:37 PM
Originally posted by profgaw101
I'm confused. The top of this thread says a G4 400 Rev A was used. Isn't that a yikes? Another post says only sawtooth will work. Which is it?

Ps - overclocked my yikes to 450 mhz using jumpers. anyone else do this?

Yes, I also have a jumper-overclocked Yikes running at 450 (problem-free for a little over two years now).

The firmware hack was done on an Sawtooth G4. The poster just made a mistake by saying it was a "Rev. A". He must have meant "Rev. B." You're right, a Rev. A. G4 400 is a Yikes without question.

jamall
Jan 26, 2004, 07:10 AM
Please read the article at xlr8yourmac again. The only way to increase the bus frequency from 100MHz to 133MHz is by removing the resistors at R434 and R435, which can be found on the back of the motherboard. These resistors are jumpers which tell the SG500 clock generator chip which frequency to operate at. A time-base problem resulted in OSes before OS 9.1 and OS 10.1.2 with the overclocked bus, which the firmware hack was designed to fix. The OF hack DOES NOT affect the speed of your computer, only the way it's speed is reported to the OS. Besides, PC100 RAM would almost certainly not run at 133MHz.

Nik_Doof
Jan 26, 2004, 07:29 AM
Originally posted by jamall
Besides, PC100 RAM would almost certainly not run at 133MHz.

Well, you could get it to run at 133, but you'd probably fry it or get some serious crash action going on :)

iEric
Jan 26, 2004, 09:48 AM
When there is an OS Update...what will happen? Anything?

profgaw101
Jan 26, 2004, 05:44 PM
Originally posted by jamall
Please read the article at xlr8yourmac again. The only way to increase the bus frequency from 100MHz to 133MHz is by removing the resistors at R434 and R435, which can be found on the back of the motherboard. These resistors are jumpers which tell the SG500 clock generator chip which frequency to operate at. A time-base problem resulted in OSes before OS 9.1 and OS 10.1.2 with the overclocked bus, which the firmware hack was designed to fix. The OF hack DOES NOT affect the speed of your computer, only the way it's speed is reported to the OS. Besides, PC100 RAM would almost certainly not run at 133MHz.

I really don't know if it actually sped up my machine or not. BUT, I can now run age of mythology on my G4, which I was unable to do before I moved the jumpers. So, if it fools the software, and still works, I'm happy.;)

Hemingray
Jan 26, 2004, 06:05 PM
Originally posted by profgaw101
I really don't know if it actually sped up my machine or not. BUT, I can now run age of mythology on my G4, which I was unable to do before I moved the jumpers. So, if it fools the software, and still works, I'm happy.;)

I think you're mixing up clock speed and bus speed. Changing the jumpers in your Yikes G4 overclocked your processor to 450MHz from 400MHz, that's all. It didn't touch your bus speed. What jamall is referring to is the bus speed only, which has nothing to do with what you did with your jumpers.

bshelly
Jan 27, 2004, 08:41 PM
Originally posted by jamall
Please read the article at xlr8yourmac again. The only way to increase the bus frequency from 100MHz to 133MHz is by removing the resistors at R434 and R435, which can be found on the back of the motherboard. These resistors are jumpers which tell the SG500 clock generator chip which frequency to operate at. A time-base problem resulted in OSes before OS 9.1 and OS 10.1.2 with the overclocked bus, which the firmware hack was designed to fix. The OF hack DOES NOT affect the speed of your computer, only the way it's speed is reported to the OS. Besides, PC100 RAM would almost certainly not run at 133MHz.

Speaking from experience, I would highly recommend you leave R434 and R435 alone. I removed them and I regret it. I am running 10.3.2 on a G4 400 and nothing is stable anymore. I have five different pairs of PC133 memory modules old and new and none of them help with the stability. Also, you will render two of your memory slots useless. I am now limited to 512mb as I can only use the two lower DIMM slots.

I will be ordering replacement resistors to solder back on as the speed increase is not worth the problems it has caused. iTunes and iMovie crash all of the time and I have yet to rip an entire disc to the hard drive.

I just need to find out what value those resistors were. If anyone knows, please send me an IM through the forum.

Thanks,
Bill Shelly

jamall
Jan 29, 2004, 11:49 PM
bshelly, the resistors don't have any resistance, they just acted as jumpers. If you didn't leave too much of a mess behind when you removed them you can simply use a conductive pen to bridge the gaps. Otherwise just solder on a length of wire. When I upped the bus multplier ratio on my processor daughter card, I found it was a lot safer to cut the traces leading to the resistors with a scalpel blade than actually remove the resistors themselves. Repairing a trace with a pen is a lot easier than resoldering a resistor. Another method I've heard of is putting a small strip of masking tape down the middle of the jumpers and drawing the connections onto the tape with the pen. It would be easier just to fork out for a Digital Audio board on ebay than risk the bus overclock. Good luck with those repairs.

PS. did you reduce the bus multiplier on your processor daughter card at the same time as the bus overclock? If not then your 400MHz processor will still be running at 4x the bus, or 533MHz, which it likely can't handle. 3.5x, or 466MHz, is probably more realistic, which involves removing R7 and R11 on your processor card (R9 should already be absent and R13 should already be in place). Hope this helps.

bshelly
Jan 30, 2004, 10:26 AM
jamall,
Thanks for the info. I wasn't sure if the resistors had any resistance. I suppose I should have measured them first to be sure. Soldering a jumper wire should not be too difficult for me, otherwise I think your idea of a conductive pen or even window defroster repair paint should work.

I did not modify the G4 400mhz card multipliers, but I also have a Giga Designs 1.4ghz chip that will work at 100 or 133mhz bus speed. At 100mhz it seemed much more stable. Sorry for not mentioning that before. I must have been tired.

I would eventually like to get a Digital Audio board, but they are a bit expensive still.

I will adjust back to 100mhz this weekend and report back on stability.

Thanks for you help!
Bill Shelly

bshelly
Jan 30, 2004, 12:28 PM
One other thing...

When I removed the resistors, I lost the ability to use all four DIMM slots. I could only use the two closest to the AGP card.

I'm not sure why that happened, but I will be back up to 1GB ram sometime this weekend.

Thanks,
Bill Shelly

hanq
Mar 9, 2004, 10:02 PM
:confused: :confused: Im sory but i haven't been paying attention to what i've been reading so far(I actually read it ALL but mind was somewhere else). so do the xbench stuff matter?? I got a 63.08 from my 400 cube that i overclocked to 533 (that I did through OF).

bshelly
Mar 29, 2004, 08:05 PM
I finally got around to soldering a jumper wire to where my resistors used to be. My system board is now back to 100Mhz Front Side Bus and everything is stable now. Too bad I cannot fully utilize this PC133 memory. Oh well. At least I can now run with a full 1GB of RAM.

-Bill

arsbanned
Mar 29, 2004, 08:36 PM
The moral of the story is:
If it ain't broke, don't fix it! :D

Oh well, good thread anyway, if a bit confused.

Dreadnought
Mar 31, 2004, 02:16 PM
i am still confused about the ram, would my pc100 still work?

It would work, but the rest of your machine will work also at 100 mhz. So you don't overclock anything then.

I have in my G3 400 B&W a 256mb 133 mhz dimm. Just curious if this works with this machine. I will try it out. I never could get it hardware overclocked. It wouldn't run stable by just altering the processorjumpers!
I'll get back to you guys as soon as possible! (hmmm, wonder if Folding@Home still works after the hack, it hates overclocked machines!)

Dreadnought
Mar 31, 2004, 03:11 PM
tooo bad, didn't work. Does anyone know how to do this with a G3 B&W? Already tried to to replace "G4" with "G3" and messing with the jumpers doesn't make it stable (won't even boot).

a1291762
Apr 9, 2004, 07:31 PM
It's completely bogus. Panther wasn't fooled in the sliightest.

I have a Sawtooth 500Mhz upgraded with a GigaDesigns Dual 1Ghz G4* (running at 1.3Ghz) that I set to 10x multiplier (1Ghz or 1.33Ghz with the overclocked bus). I tried the openfirmware hack and I got nothing. No performance increase, not even different numbers reported for bus/cpu speed. I checked on the hardware prefpane and the "About this Mac" page.

I think the comment (#64) that says this is for fooling earlier OSes (which didn't handle the timebase properly) into seeing your *hardware* bus overclock must be correct.

* Asutute readers will note that I don't have my PowerLogix CPU anymore. Alas, it didn't like my machine (prevented it from sleeping) so I sent it back and got this one instead. Even better, I paid less money for a vastly superior CPU.

a1291762
Apr 9, 2004, 07:33 PM
(hmmm, wonder if Folding@Home still works after the hack, it hates overclocked machines!)

Programs like Folding@Home push your hardware to the limits. Compiling large projects will also do this. If F@H is crashing on your overclocked hardware, it's because your hardware isn't stable.

I had an old Pentium 3 that had been overclocked and it worked fine until I tried to compile stuff when the compiler would crash. Un-overclocking it made everything work fine.

Link

ingenious
Apr 9, 2004, 10:19 PM
Sorry, here is the screen shot. I will do xbench now and compare the results.

ever think of updating to 10.2.8? it worked sooo much better for me before i got panther.

Alte22a
Apr 26, 2004, 08:30 PM
just used open firmware on mine. I get G2 dual dual 1.08 bus speed@167. I am not sure if its faster but I did score alower make on Xbench. Its all very confusing.

disconap
Oct 30, 2005, 12:16 AM
So I realize this is an old thread, but did anyone ever get this to work? I have a Sawtooth 400 that is starting to run a bit sluggish in 10.3.9 and I wouldn't mind bumping it for a little while until I can afford a processor upgrade...

Basically, does anyone have any real-time answers? Some have already said it foold the software tests, so can anyone confirm that they've noticed a difference in performance, especially in Illustrator?

AP_piano295
Oct 30, 2005, 12:29 AM
could u post some benchmarks?

Lacero
Oct 30, 2005, 12:32 AM
I overclocked my old Pentium 150Mhz PC to 166Mhz hoping it would die, so I can get a new PC. :p But unfortunately, the machine is still running 8 1/2 years on, so I am out of luck on getting another PC.

Make sure the G4 gets a lot of cool ventilation, which might mean prying it open or replacing the case fan with something more powerful.

disconap
Oct 30, 2005, 12:32 AM
I haven't tested the hack yet, I'm in the middle of my work "day" and just stumbled across the thread. I'll gladly do it later tonight or tomorrow, though.

disconap
Oct 30, 2005, 12:33 AM
I mod with every scrap I have. I think my G4 has 3 or 4 fans currently...

disconap
Jan 23, 2006, 09:08 PM
Bumping this as Lowendmac has an article up about adding DIP switches to overclock the G4 Sawtooth bus speed. Anyone have any luck with this? I was thinking of trying it out, but would rather pick up a test tower first...

Also, if anyone knows about the L2 cache boost? Would that be necessary with a non-Apple processor (i.e., a Sonnet upgrade)?

Article: http://www.lowendmac.com/macdan/05/1130.html

Meyvn
Jan 23, 2006, 10:15 PM
Could there be a hack like this on newer models, even if this particular one doesn't work?

disconap
Jan 24, 2006, 01:18 PM
Of G4s? Possibly; a lot of these hacks work well, and some don't, but it's all about experimenting (which is why we get stuff like this years after the model is new, as who is going to risk a $3000 machine on a hunch?). If the DIP configuration is the same, I don't see why it wouldn't...

me hate windows
Mar 18, 2006, 03:24 AM
It isn't all that hard to actually hardware overclock these things. I overclocked two of them to 500 Mhz just by removing a resistor. All you need is a little soldering experience.
http://power-mac-g4.com/g4clockup.html

mmmcheese
Mar 18, 2006, 12:02 PM
Yeah, I do.

I have a Sawtooth G4 500, processor upgraded to 1.3Ghz, with the processor jumpers set for a 100Htz bus, anyone know how applying this hack would affect that?

You would have to change both the jumpers on the card, and the OF setting. This is pretty straight forward overclocking, PC enthusiasts have been doing this for years. The OP's experience isn't that abnormal. Every machine is different, so one person might get a 25% overclock, while someone else won't get any.

jimstem
Mar 28, 2009, 04:04 PM
It worked! I booted into open firmware (cmd opt O F), typed the commands, and rebooted and now system profiler shows a 533GHz G4! :) And it does even feel peppier! And I only have a single 128MB PC100 ram chip in.....how about that!

aibo
Mar 28, 2009, 05:53 PM
What the... 3 year old thread?

How much difference is going from 400MHz to 533Mhz going to make nowadays, as far as aiding in ability to run any modern software?

rbellinge
Jul 1, 2009, 11:26 PM
I just signed up purely so I could say, I followed the OP instructions, and bingo bango, I went from 400MHz to 533MHz. SAWEET.

Running a G4 (AGP Graphics), so pretty happy with it now. Seems to run a little quicker, I think.

I discovered this comp collecting dust in an old farm shed in outback Australia, and how its running Tiger, got a 2nd SATA HDD (using a SATA/IDE converter), and is the server at home, stable, quiet, reliable. Awesome!

Question though; is this fix just tricking the software to read an overclock, or is the processor ACTUALLY running faster? Im new to all this (but learning fast!) and have been considering whipping out the soldering iron and giving this a shot too:

http://power-mac-g4.com/g4clockup.html

Brave, or stupid?

Cheers all!

Andrew Henry
Jul 2, 2009, 01:50 AM
I just signed up purely so I could say, I followed the OP instructions, and bingo bango, I went from 400MHz to 533MHz. SAWEET.

Running a G4 (AGP Graphics), so pretty happy with it now. Seems to run a little quicker, I think.

I discovered this comp collecting dust in an old farm shed in outback Australia, and how its running Tiger, got a 2nd SATA HDD (using a SATA/IDE converter), and is the server at home, stable, quiet, reliable. Awesome!

Question though; is this fix just tricking the software to read an overclock, or is the processor ACTUALLY running faster? Im new to all this (but learning fast!) and have been considering whipping out the soldering iron and giving this a shot too:

http://power-mac-g4.com/g4clockup.html

Brave, or stupid?

Cheers all!

Do you realize that this thread is from 2003?

macz1
Jul 2, 2009, 02:59 AM
The only way to overclock a G4 is moving some PLL resistors which control the frequency multiplier.
The firmware trick will do NOTHING in terms of speed, it only leads the system to read a different value for the bus clock than it actually is...
The only thing which could happen are timing problems or similar things when playing audio and movies...

On Sawtooth you can modify the bus speed by means of a DIP switch, though. You have to install it near the RAM slots, there is an article somewhere.

Good luck anyways.