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v-i-c-
Sep 18, 2004, 10:05 AM
hello

i want to put an 1.8 ghz g5 processor (cause i have no other processor) on a 1.6 g5 mainboard. will that work? (i don't want it to run at 1.8ghz - 1.6 is enough - i just want to bring the g5 mainboard to life)

:confused:



jared_kipe
Sep 18, 2004, 10:53 AM
I think it will work, but man, what an odd thing to do. Where did you get the parts for that?

v-i-c-
Sep 18, 2004, 11:41 AM
i got some parts on ebay

Dreadnought
Sep 18, 2004, 07:21 PM
let us know how it worked out. I think you are the first that will try it!

Sun Baked
Sep 19, 2004, 03:32 PM
Is there a third-party Thermal Calibration program around?

Important: Whenever you replace a processor with a new processor, you must run Apple Service Diagnostic (once the computer is reassembled). You must also run the diagnostic if you re-install the same processor but in a different connector from the one in which it was originally installed. Apple Service Diagnostic for Power Mac G5 is available as a download from the Disc Images section of the Apple Service Source website. For more information, see “Thermal Calibration” in the Troubleshooting chapter.

v-i-c-
Oct 3, 2004, 10:26 AM
ok - i got most of the parts that i need for my frankenstein G5 (1.6/1.8) - just need the screws and the graphicscard now - for the first attempt to bring the G5 to live i want to use an old graphicscard: the ati rage 128 (agp) from an old G4

any idea if i run in trouble using this card? i heared that older agp-cards needs different voltages and that they can damage modern mainboards - is that true? has anyone ever tried to put such an old card into a G5?

Mord
Oct 3, 2004, 12:58 PM
yeah dont do it older cards run at much higher voltages, if your cheap get a 5200 off ebay if your adventurous buy a pc 9800 and flash it (it's not to hard if you have a pc and there are no resistor moves or anything like that) if your rich get a 9800se mac edition for $$$$.

keysersoze
Oct 3, 2004, 01:26 PM
ok - i got most of the parts that i need for my frankenstein G5 (1.6/1.8) - just need the screws and the graphicscard now - for the first attempt to bring the G5 to live i want to use an old graphicscard: the ati rage 128 (agp) from an old G4

any idea if i run in trouble using this card? i heared that older agp-cards needs different voltages and that they can damage modern mainboards - is that true? has anyone ever tried to put such an old card into a G5?

Hey- If you want an original nVidia GeForce 5200 Ultra, I've got one. This originally came with a 1.6 Ghz G5... if you are interested, PM me.

v-i-c-
Oct 3, 2004, 05:57 PM
thx

as written in my PM to you it's to expensive to buy small parts in u.s. for europeans cause the bank wants to much money for the transfer :(

but i got an geforce 5200 ultra (from a g5) just some minutes ago on ebay for 60,- :D

v-i-c-
Feb 8, 2005, 11:47 PM
ok it took me a little bit to get all parts but finally it works - YOU CAN UPGRADE YOUR G5 1.6 to 1.8GHz with a new processor - systembus will raise to 900mhz too!

i did it this night :D

look here:

Building an 1.8GHz PowerMac G5 using an 1.6GHz Mainboard (http://www.warbirds-pilots.com/offi/g5/)

v-i-c-
Feb 9, 2005, 01:12 PM
don't try it! - calibration will not work because processor is to fast - need help - any oher way to "calibrate" fans?

keysersoze
Feb 9, 2005, 01:58 PM
don't try it! - calibration will not work because processor is to fast - need help - any oher way to "calibrate" fans?

Wow- great pictures.

No clue on calibration, but the construction of your machine is impressive.

v-i-c-
Feb 9, 2005, 02:09 PM
just found this on the web

"the G5 is second only to the Power
Macintosh G4 Cube in terms of noise when everything is working
properly. Similarly, the G5 is second only to an F-16 on afterburner
when the system has sensed an error.

If there is a temperature-sensing
problem in the G5, the system employs a fail-safe feature to ensure you
don't burn up the computer. As some of you may know, the fail-safe
procedure is to turn ALL the fans on and set the fan speed to
"deafening" while slowing the processors down to 1.3GHz."

http://www.smalldog.com/newsarchive/techtails_display.php?id=207

run some tests - looks really like working in energy save mode all the time! maybe i have to "flash" the board?? to prevent that fail save feature?

thecow
Feb 9, 2005, 02:29 PM
yeah dont do it older cards run at much higher voltages, if your cheap get a 5200 off ebay if your adventurous buy a pc 9800 and flash it (it's not to hard if you have a pc and there are no resistor moves or anything like that) if your rich get a 9800se mac edition for $$$$.If you flash the 9800 pc, will it work in a MDD PowerMac G4? Do you have detailed instructions on how to do this?

Sun Baked
Feb 9, 2005, 02:56 PM
don't try it! - calibration will not work because processor is to fast - need help - any oher way to "calibrate" fans?You might want to ask Hector why the calibration program on the Apple service disk (for Service Techs) didn't work.

The calibration needs to be run any time a new CPU module is plugged in, even one of the same speed.

Mord
Feb 9, 2005, 03:33 PM
If you flash the 9800 pc, will it work in a MDD PowerMac G4? Do you have detailed instructions on how to do this?

http://strangedogs.proboards40.com/index.cgi?board=experiments


as for the thermal calibration i still have the cd if you want it contact me on AIM, i live in london so i could post a copy to you

v-i-c-
Feb 9, 2005, 05:43 PM
i allready used the apple service calibration cd - all tests ok.
but before i can start all the tests the app shows this directly after the ASD app started:

"THERMAL CALIBRATION ERRORS DETECTED

MLB bus speed is less than CPU0 bus speed: MLB 800MHZ CPU0 900

Replace CPU, restart Mac, Run ASD, Press Calibrate button to calibrate this Macintosh.

Calibration will take 10 to 20minutes to finish"


below that there are 3 buttons:

"calibration skip shutdown"


i can press "calibration" (it's not greyed out) but nothing happens when i press it - nothing changes on the screen and i can hear no difference from the fans like in the tests later when it tests sensors and fans itself.

when i press "skip" screen changes to the normal ASD test screen but jumps back to this error screen - this happens only 1 time - next time i press skip it stays on the screen with the normal service tests

looks like unless i find a jumper or a firmware update to tell the board that it's ok to run at 900mhz ;) i have no chance to use the board and the processor at normal speed (1.6 or 1.8) - it will stuck at 1310mhz CPU and 655mhz bus speed with fans running at high speed (which is MUCH louder than my other G5 ever was) - i know there was a website that showed some jumpers that can be soldered (but no chance for me to solder such small parts :( ) to tell the processor it's speed:

http://24.13.230.40/overclock/g5.html

- at this moment i would be glad if there is a way to tell the 1.8ghz processor board to run at 1.6ghz without soldering - for the first time it would be also ok to get these fans under control - isn't there a way to read out the calibration of another g5 and flash it into another one? or maybe flashing the board or something like that - isn't there any way to prevent this fail-safe feature?

or maybe is there someone out who wants to exchange a 1.6ghz G5 processor to my 1.8? ;)

combatcolin
Feb 9, 2005, 05:49 PM
Needs balls to fiddle with all this expensive gear, not easy nor cheap to get hold of.

Sun Baked
Feb 9, 2005, 05:56 PM
You may want to e-mail Michiro Isobe and see if he has heard of any "motherboard" jumpers that need to be changed.

Remember the G5 is a bit different than the G4, the Memory Controller and the support processor do a heck of a lot more than they did in the G4.

This error looks like it's telling you there is a difference between what the Memory Controller is clocking in at, and what the CPU module says it can run at.

Edit: and I do mean motherboard, not the jumpers on the CPU module.

NZ_Machine
Feb 10, 2005, 02:47 AM
Hi, I'm VIC's Brother and it's "my" Mac. :D

My favorite solution ist to tell the board to shut it's mouth and run at the
FSB we want him to. If there is no way at all, a friend of mine is a genius
in soldering. For example: he overclocked the old AMD Athhlons by solder
a microscopic wire to the jumperbridges of the CPU. He told me, he's not
blind, therefore it's easier to solder than to use a stencil. :eek:

How did the other guys overclock their g5s without changing anything on the
logicalboard to get a higher FSB?

I dont't like to downgrade a CPU, because all of my PCs are running at a
higher speed than the manufactor wants to. :cool:

What a shame to tell my collegues at NetZock, that my Mac can't be
overclocked. They will ROTFL and telling my that Mac ist crap. :rolleyes:

There MUST be a solution!

TIA
Kind Regards
Michael

jackieonasses
Feb 10, 2005, 02:53 AM
just found this on the web

"the G5 is second only to the Power
Macintosh G4 Cube in terms of noise when everything is working
properly. Similarly, the G5 is second only to an F-16 on afterburner
when the system has sensed an error.

If there is a temperature-sensing
problem in the G5, the system employs a fail-safe feature to ensure you
don't burn up the computer. As some of you may know, the fail-safe
procedure is to turn ALL the fans on and set the fan speed to
"deafening" while slowing the processors down to 1.3GHz."

http://www.smalldog.com/newsarchive/techtails_display.php?id=207

run some tests - looks really like working in energy save mode all the time! maybe i have to "flash" the board?? to prevent that fail save feature? The windtunnel (mirror-drive doors) was the noisest. I don't see how you can say the cube is loud considering, it has no fans at all.

kyle

Platform
Feb 10, 2005, 03:45 AM
ok it took me a little bit to get all parts but finally it works - YOU CAN UPGRADE YOUR G5 1.6 to 1.8GHz with a new processor - systembus will raise to 900mhz too!

i did it this night :D

look here:

Building an 1.8GHz PowerMac G5 using an 1.6GHz Mainboard (http://www.warbirds-pilots.com/offi/g5/)

WOW

That was really cool, Would like to try myself how much did it total up to :confused:

edit: but it does not seem to work that well. or is it just the fan noise :confused:
How about if you have bought a SP PM can you later add another cpu to the board :confused:

v-i-c-
Feb 10, 2005, 12:49 PM
How about if you have bought a SP PM can you later add another cpu to the board


that's the point here - if we get rid of the problems the answer is: yes

edit: but it does not seem to work that well. or is it just the fan noise

ok maybe i should explain it again:

Apple Service Diagnostic Tests worked well - all tests passed.
the hardware is in perfect condition and the computer is also working perfectly with OS X but there are 2 issues:

i cannot run thermal calibration in the Apple Service Diagnostic Software because the G5 is in a kind of safe mode. this safe mode is activeted because the firmware recognized that the board bus is to slow for the processor bus. that safe mode causes to run the G5 at a speed of 1.31 MHz instead of 1.6/1.8 and 655mhz bus frequency instead of 800/900, it also turns on all the fans at their full speed.

for this problem there should be 6 ways to fix it:


1. i buy a 1.6 processor and sell the 1.8 on ebay (will work for sure)

2. i buy a 1.8 single (2003) mainboard and sell the 1.6 single board on ebay (will work for sure)

3. some king of soldering helps us and solder the jumpers on the processor board (like shown on that website - link above) that the processor runs with 1.6 mhz and 800mhz bus.

4. some king of soldering helps us and solder the jumpers on the processor (how????) that the processor speed is still 1.8ghz but bus speed is set to a lower setting than the max mainboard bus speed is (maybe 600mhz like the "new" G5 single 1.8)

5. someone finds out how to overclock the mainboard speed to 900mhz (soldering or not soldering)

6. the way i would prefer (but no big hope): i find a way to patch the firmware of the G5 that this "safety mode" will not be activated and/or i find an app that gives me control over fans and processor speed (which is possible but i think not existent yet)


I NEED HELP! 1&2 is the last solution that i can afford because it costs $$$ again and this G5 was only a few $100 cheaper than a new 1.8 single and i still want to see it below that price.

btw: here you can see how it performs vs a new single 1.8GHz (which was on reduced speed settings):

http://ladd.dyndns.org/xbench/merge.xhtml?doc1=96222&doc2=96375

this is the result compared to the same machine at high settings (and the frankenstein G5 still stuck at it's low settings):

http://ladd.dyndns.org/xbench/merge.xhtml?doc1=96222&doc2=96376




The windtunnel (mirror-drive doors) was the noisest. I don't see how you can say the cube is loud considering, it has no fans at all.

i didn't said that - Duane Letourneau said it in "G5 Thermal Management"

he wanted to say that the G5 is really a quiet Mac and that there is only the cube which is more quiet (and some iMacs and iBooks ;)) - the G5 is not louder than the G4 MDD normally but when this "safety mode" is activeted and the fans are running really at it's full speed then it's louder than everything i ever heared - (i have the dual 2.5GHz whith GeForce6800 ultra DDL which is the loudest G5 - the liquid cooling system doesn't reduce noise because there are still all that fans in the machine and the gf6800 is loud too - the dual 2.5 is nothing compared to the other G5 in it's safety mode, i would say it's feels 10 times louder than the 2.5 at it's highest sound level)

jackieonasses
Feb 10, 2005, 01:04 PM
i didn't said that - Duane Letourneau said it in "G5 Thermal Management"

he wanted to say that the G5 is really a quiet Mac and that there is only the cube which is more quiet (and some iMacs and iBooks ;)) - the G5 is not louder than the G4 MDD normally but when this "safety mode" is activeted and the fans are running really at it's full speed then it's louder than everything i ever heared - (i have the dual 2.5GHz whith GeForce6800 ultra DDL which is the loudest G5 - the liquid cooling system doesn't reduce noise because there are still all that fans in the machine and the gf6800 is loud too - the dual 2.5 is nothing compared to the other G5 in it's safety mode, i would say it's feels 10 times louder than the 2.5 at it's highest sound level) oh! i understand now. Thanks for clarifying. I had a Single 1.8 and when that thing went to full speed - It sounded insane.


kyle

Mord
Feb 10, 2005, 01:34 PM
The windtunnel (mirror-drive doors) was the noisest. I don't see how you can say the cube is loud considering, it has no fans at all.

kyle

he's saying the only mac quieter than the G5 is the cube.

no computer on the planet is quieter than a g4 cube with a flash based HD (you can get them they are very expensive).

Sun Baked
Feb 10, 2005, 05:23 PM
If you don't want to contact Isobe, here's BadAndy's (http://episteme.arstechnica.com/eve/ubb.x/a/tpc/f/8300945231/m/9080959175/r/290002769631#290002769631) guess.

There is another small service Processor in our G5 Tower and it's hooked to I2C...

You may have to flash the ROM on the service processor, if there isn't a jumper on the motherboard.

Edit: POR is also on IBM's site (http://www-03.ibm.com/chips/products/powerpc/newsletter/dec2004/ppc_process_at_work2.html)...

http://www-03.ibm.com/chips/products/powerpc/newsletter/dec2004/images/mvd_1.gif

The power-on reset (POR) logic of the IBM PowerPC® 970FX processor is more sophisticated compared to previous PowerPC processors that rely on jumpers to select operation modes. The PowerPC 970FX processor initialization is controlled by a pervasive logic that requires communication with an external service processor through an I2C bus.

Platform
Feb 11, 2005, 04:10 AM
that's the point here - if we get rid of the problems the answer is: yes

1. i buy a 1.6 processor and sell the 1.8 on ebay (will work for sure)

2. i buy a 1.8 single (2003) mainboard and sell the 1.6 single board on ebay (will work for sure)

I NEED HELP! 1&2 is the last solution that i can afford because it costs $$$ again and this G5 was only a few $100 cheaper than a new 1.8 single and i still want to see it below that price.

this is the result compared to the same machine at high settings (and the frankenstein G5 still stuck at it's low settings):

http://ladd.dyndns.org/xbench/merge.xhtml?doc1=96222&doc2=96376




Thanks for the explanation

I saw on the pictures that the new/2nd cpu is just hoocked up to the mother-board with 4 scrwes. but is it connected to the MB trough those or did I miss some wire :confused:

isgoed
Feb 11, 2005, 05:54 AM
1. i buy a 1.6 processor and sell the 1.8 on ebay (will work for sure)

2. i buy a 1.8 single (2003) mainboard and sell the 1.6 single board on ebay (will work for sure)

3. some king of soldering helps us and solder the jumpers on the processor board (like shown on that website - link above) that the processor runs with 1.6 mhz and 800mhz bus.

4. some king of soldering helps us and solder the jumpers on the processor (how????) that the processor speed is still 1.8ghz but bus speed is set to a lower setting than the max mainboard bus speed is (maybe 600mhz like the "new" G5 single 1.8)

5. someone finds out how to overclock the mainboard speed to 900mhz (soldering or not soldering)

6. the way i would prefer (but no big hope): i find a way to patch the firmware of the G5 that this "safety mode" will not be activated and/or i find an app that gives me control over fans and processor speed (which is possible but i think not existent yet)I have never done anything like this, but here is what I think:

6. doesn't work. There is no way an 1.8Ghz CPU will work with a 800mhz bus.
3. seems the easiest solution. When the processor presents itself as an 1.6 Ghz processor the logic board will probably just accept it.
4. Is the coolest solution, but probably the most difficult since you need to change the bus speed, the processor multipliers, ram multipiers (if they have those) and maybe even the flashrom. If you got it working though, there is even the foresight of running at speeds above 1.8 Ghz, which would be ultra-cool.

v-i-c-
Feb 11, 2005, 05:55 AM
saw on the pictures that the new/2nd cpu is just hoocked up to the mother-board with 4 scrwes. but is it connected to the MB trough those or did I miss some wire

i wish i had an 1.6 processor :( - but i only got an 1.8 so it's not a "new/2nd" processor...

right the processor is fixed on the mainboard using 4 special screws.
it's connected to the mainboard with a kind of multipin slot under the processor board - no wires



@Sun Baked:

any further idea if there is really the possibility to flash that service processor?

do you have the email of Isobe?

Sun Baked
Feb 11, 2005, 07:06 AM
@Sun Baked:

any further idea if there is really the possibility to flash that service processor?

do you have the email of Isobe?Don't know if it's a flash for each bus speed, or a resistor setting (telling the service processor which settings table to use).

You sort of need to compare a 1.6MHz and 1.8MHz board -- and Apple did reship some 1.8MHz machines as 1.6MHz machines when the killed the SP 1.8 the first time.

They also disabled PCI-X on them, so it must be possible to either flash them or move jumpers.

---

He's a member on ARStechnica (M.Isobe), and widely found by doing a google search using "Michiro Isobe AND overclocking"

There is also a thread on ARS you might want to drag back up to the top...

Over-Clocking the PowerMac G5 Thread (http://episteme.arstechnica.com/eve/ubb.x?a=tpc&s=50009562&f=8300945231&m=833008904631)

v-i-c-
Feb 12, 2005, 08:00 PM
No answer from M. Isobe yet...

anyone else with new ideas or infos?

Sun Baked
Feb 12, 2005, 08:08 PM
No answer from M. Isobe yet...

anyone else with new ideas or infos?Join ARS and drag the thread back to the top, ARS is generally more technical than here.

v-i-c-
Feb 12, 2005, 09:42 PM
i joined - but the thread is an archived thread now - so no new postings alowed - i also started a new thread there http://episteme.arstechnica.com/eve/ubb.x/a/tpc/f/8300945231/m/721002389631

Platform
Feb 12, 2005, 11:08 PM
i wish i had an 1.6 processor :( - but i only got an 1.8 so it's not a "new/2nd" processor...

right the processor is fixed on the mainboard using 4 special screws.
it's connected to the mainboard with a kind of multipin slot under the processor board - no wires



@Sun Baked:

any further idea if there is really the possibility to flash that service processor?

do you have the email of Isobe?

Thanks for that

Hope your project turn out well, becasue then we might see more people building costom G5's :D

v-i-c-
Feb 14, 2005, 07:14 AM
i'll try to install yellow dog linux on the g5 today - just to see if the linux fan driver will slow down the fans.

v-i-c-
Feb 17, 2005, 02:33 PM
yes fans run fine under linux - no vacuum cleaner sound anymore - yellow dog linux shows 1800MHz as processor speed but since osx said the same i don't trust that. i need to find some benchmarks and comparison charts of other G5 1.8 or 1.6 to see how fast it really is - any idea?

it really looks like i need a new kernel extension for thermal management now. but that's not existent.

btw: there was an major update to the selfmade G5 1.8 on a 1.6 Logicboard (http://www.warbirds-pilots.com/offi/g5) site

Platform
Feb 18, 2005, 03:44 AM
yes fans run fine under linux - no vacuum cleaner sound anymore - yellow dog linux shows 1800MHz as processor speed but since osx said the same i don't trust that. i need to find some benchmarks and comparison charts of other G5 1.8 or 1.6 to see how fast it really is - any idea?

it really looks like i need a new kernel extension for thermal management now. but that's not existent.

btw: there was an major update to the selfmade G5 1.8 on a 1.6 Logicboard (http://www.warbirds-pilots.com/offi/g5) site

I like what you have done to your web page ;)
Hope that you will be able to get the fans normal in OS X.
By the way how does Linux work on mac :confused:

v-i-c-
Feb 21, 2005, 03:04 AM
By the way how does Linux work on mac

i used Yellow Dog Linux for PPC they have a version with thermal drivers for the G5. i don't really know if it's really running at 1.8GHz now - i found a benchmark but it crashed while running lol - there is a kind of system overview which shows bogomips and i compared this value with some that i found with google, but i didn't found bogomips of a G5 1.8 running YDL, so i calculated it and it looks like it's a faster than 1.31GHz but slower than 1.8GHz. so maybe YDL is faster today (i use 4.0) or faster than other linux for PPC because i think those values i found was from other linux versions. maybe someone can help out with his YDL 4.0 G5 1.8GHz values? anyway it works fine and it's really quiet. but it's no solution for me because we want to use the mac as a mac.

v-i-c-
Mar 7, 2005, 12:40 PM
looks like it runs @1.6GHz using YDL / maybe someone found the Logicboard jumpers! more on the http://www.warbirds-pilots.com/offi/g5

andypress
Mar 8, 2005, 04:56 PM
he's saying the only mac quieter than the G5 is the cube.

no computer on the planet is quieter than a g4 cube with a flash based HD (you can get them they are very expensive).
That and the iMac DV 400mhz. Convection cooled as well.

Mord
Mar 8, 2005, 05:01 PM
the hum of the CRT :P

Sun Baked
Mar 8, 2005, 05:03 PM
Remember there will also be a bank of jumpers for the HT PCI-X controller (which could/should enable PCI-X on the 1.6 board)

Edit: Remember I asked for some pics of this controller (or the part number and manufacturer) if you can find it, which should be where the majority of the PCI trace go.

BadAndy hoped there was a hash table controlled by jumpers... hopefully this does turn out to be the case.

Sun Baked
Apr 3, 2005, 07:09 PM
You might want to try M.Isobe again, he's posting once again on ARS.

SpeedKills
Apr 14, 2005, 04:46 AM
Hi Chaps,

I'm really sorry to ask a favour on my first post here, I know it's not the done think on forums, but I desperately need the Apple Calibration Software to stop the McDonnell-Douglas Boeing type fans on my G5. I've replaced a faulty 1.8 processor and the thing sounds like it's going to taxi across the room and head for the window.

Can anyone post a link to this software ? Please, for the sake of my ears.

Steve

v-i-c-
Apr 16, 2005, 10:37 AM
And? Did you solved your problem with your G5 SpeedKills?

v-i-c-
May 10, 2005, 06:57 AM
now it's running quiet but still at 1.3GHz. :) my brother disconnected all fans and reconnected them one by one to see if it can work with less fans. seems like the G5 fans ignore the failsafe mode when the HD Bay fan is disconnected. still no 1.8GHz but a working machine without noise problems.

Platform
May 10, 2005, 07:26 AM
now it's running quiet but still at 1.3GHz. :) my brother disconnected all fans and reconnected them one by one to see if it can work with less fans. seems like the G5 fans ignore the failsafe mode when the HD Bay fan is disconnected. still no 1.8GHz but a working machine without noise problems.

Good to hear that is is working but hope that you will get the extra 500Mhz :rolleyes:

Sun Baked
Jul 2, 2005, 07:15 PM
New member came by and updated v-i-c-'s ARS thread, should give people a hint of the problems one can encounter in OCing a PPC970.

http://episteme.arstechnica.com/eve/ubb.x/a/tpc/f/8300945231/m/721002389631

Not a job for a novice with a soldering iron. But some good ideas for cracking the Service Processor and the ROM/jumpers.

MacTruck
Jul 2, 2005, 07:26 PM
I thought all macs use the exact same motherboard. I thinks I is right!

Sun Baked
Jul 2, 2005, 08:46 PM
I thought all macs use the exact same motherboard. I thinks I is right!Now that they got rid of the iMac-based Single processor Powermac the number of boards dropped from 3 to 2.

The single processor Rev. B used a iMac chipset. U3-Lite & Shasta.

The Rev. B duals have a PCI-X and a PCI version, the PCI version lacks the PCI-X controller and taps PCI from the K2 controller.

The Rev As were all one board design and Apple populated them in various configurations. Single CPUs lacked the 2nd socket, and PCI versions just had a different jumper setting that limited the PCI-X controller to PCI speeds.

---

So that would be 4 major board designs total for the 2 generations of PM G5.

The Rev. B duals used 2 different memory controllers U3 & U3H, the Rev. C duals all use the U3H with the PCI version still deleting the PCI-X Controller.

v-i-c-
Apr 28, 2006, 11:12 PM
story goes on - ordered a 1.8 Mainboard yesterday :D

tonyl
Apr 29, 2006, 12:02 AM
Great! Looking forward to your results!

v-i-c-
May 2, 2006, 04:08 AM
I also ordered a 1.6 processor without heatsink yesterday to use the old 1.6 board with it to build up a 2nd frankenmac. Does anyone have a complete HEATSINK (with all partes needed) or a DEAD Processor with heatsink? (the heatsink is the last missing part that i need)

agent 86
May 14, 2006, 10:01 PM
ok it took me a little bit to get all parts but finally it works - YOU CAN UPGRADE YOUR G5 1.6 to 1.8GHz with a new processor - systembus will raise to 900mhz too!

i did it this night :D

look here:

Building an 1.8GHz PowerMac G5 using an 1.6GHz Mainboard (http://www.warbirds-pilots.com/offi/g5/)
Did you need to use that icecream scoop?