Question on CPU's for MAc G5 2.5

[Session18]

Hello,

I'm new to the forum and have a question regarding the cpu's on my G5. I have an old G5 2.5ghz running OS 10.4.9 that I purchased new in 2005 and use it for recording music only.

Here is the info on my computer:
M9457LLA G5 Dual 2.5Ghz
Power Mac 7.3
Model # A1047 Emc#1969C

I thought that this computer had two CPU's but when I looked at "ABOUT THIS COMPUTER"> "Hardware Overview" it shows only 1 cpu. Should this computer show two or one Cpu's? or is it only showing one because one has failed ? Any info would be appreciated!

Thanks

 

[pl1984]

Based on the serial number and model it should have two CPUs.

 

[Session18]

Based on the serial number and model it should have two CPUs.

Thanks for the reply! Yes, that's what I though it should show , but I contacted Apple support today and they said it should show only one. I'm a little confused, I'm about ready to order a replacement Dual Processor but I'm not sure what to do

 

[pl1984]

Thanks for the reply! Yes, that's what I though it should show , but I contacted Apple support today and they said it should show only one. I'm a little confused, I'm about ready to order a replacement Dual Processor but I'm not sure what to do

IBM also made a dual core 2.5GHz G5 processor however it was only used by Apple in their PowerMac G5 Quad. The only other 2.5GHz PowerMac used dual, single core G5 processors. You can view the build configuration of your Mac using this link:

http://www.appleserialnumberinfo.com/Desktop/index.php

 

[AphoticD]

It can be a pain to do, but I would suggest you take the CPU units out of the tower, clean and then reseat them.

While you have them out, it would be a great opportunity to put fresh thermal paste on the CPU dies.

I went through this process on my G5s not long ago;
https://forums.macrumors.com/threads/power-mac-g5-dust-out-and-thermal-paste-re-do.2097720/

Does your model G5 use a Liquid Cooling System? If so, it would be worth doing a thorough inspection for any signs of coolant leaks.

 

[bunnspecial]

IBM also made a dual core 2.5GHz G5 processor however it was only used by Apple in their PowerMac G5 Quad. The only other 2.5GHz PowerMac used dual, single core G5 processors. You can view the build configuration of your Mac using this link:

Another quirk of the dual-core G5s:

OS X reports the cores as separate CPUs. Thus, the dual core 2.0 and 2.3 report 2 separate processors, and the Quad reports four.

 

[Bubalight]

Since the dual 2.5 used a terrible liquid cooling system it has undoubtedly leaked and probably corroded things on the lower CPU to smithereens. It is astounding that the computer even turns on, and it would be shocking if you could ever get it back to be fully functioning.

 

[Hrududu]

Yeah, you're supposed to be showing 2 CPUs. Could be that one CPU has failed, or the logic board is failing. As AphoticD mentioned, its absolutely worth taking a chance on removing/reseating the CPUs to see if you've just got a bad connection at the socket. Good luck!

 

[Session18]

Thanks for the replies! So here's the update on my problem..

I found and ordered a new complete processor, it came Friday. I had a former Apple tech come to installed the used processor. After he ran the ASD, the system still showed only 1-Cpu. He ran some more tests and said the Logic board appears to be good, so it was probably a bad Cpu on the unit I purchased. So he pulled that back out and re-installed mine, after cleaning and re-installing the Cpu's with fresh Thermal Paste on the processor. He re-install my old unit , ran the ASD and still the same , the computer shows 1-Cpu. I located another complete processor that they give you a 60 day warranty on it. Did you think it's worth another shot or should I just call it quits. The computer is still running well on 1-Cpu, but I don't know for how long.

 

[Hrududu]

Have you tried swapping the known good CPU into the other socket? I feel like that’s where the problem lies

 

[Session18]

Have you tried swapping the known good CPU into the other socket? I feel like that’s where the problem lies

[doublepost=1538941313][/doublepost]Do you mean, maybe a problem with the socket on the logic board? I'm not sure how to tell which is the good CPU on the processor.

 

[pl1984]

Thanks for the replies! So here's the update on my problem..

I found and ordered a new complete processor, it came Friday. I had a former Apple tech come to installed the used processor. After he ran the ASD, the system still showed only 1-Cpu. He ran some more tests and said the Logic board appears to be good, so it was probably a bad Cpu on the unit I purchased. So he pulled that back out and re-installed mine, after cleaning and re-installing the Cpu's with fresh Thermal Paste on the processor. He re-install my old unit , ran the ASD and still the same , the computer shows 1-Cpu. I located another complete processor that they give you a 60 day warranty on it. Did you think it's worth another shot or should I just call it quits. The computer is still running well on 1-Cpu, but I don't know for how long.

I wouldn't trust the ASD to save my life. Symptoms are pointing to a bad motherboard. If you're OK with the performance of running a single processor then by all means continue to use it. I recently discovered half the RAM slots in my 2.3GHz G5 are bad. I've had it for a couple of years and it's still chugging along fine (though I do not use it regularly).

 

[AphoticD]

[doublepost=1538941313][/doublepost]Do you mean, maybe a problem with the socket on the logic board? I'm not sure how to tell which is the good CPU on the processor.

I agree with trying @Hrududu ‘s idea of swapping the processors around to pinpoint the failure.

On your Dual Processor G5, each Processor Card holds a single CPU, so you want to try isolating the CPUs to determine what is faulty.

My understanding of the G5s is that the top processor socket must have a working CPU card in order to boot, so with this mind;

1. First up, use a marker to label your CPUs with A (top) and B (bottom).
2. We are expecting slot A on the logic board to be working or else the G5 won’t POST. So, confirm this by removing CPU B from the bottom socket and booting it up.
3. Shut down and remove CPU A from the top slot.
4. Install CPU B into the top slot and boot - if it POSTs okay at this point then we know both CPU cards are okay.
5. For fun, shut down and try reinstalling CPU A into the bottom slot (swapping the original config). Boot up and see if you still only have 1 CPU active or possibly 2.

This process will determine that the fault is not with your CPU cards and points to a logic board fault as per @pl1984 ‘s reply.

If this is the case, you should be able to source any of the PowerMac7,3 boards which utilize 8 RAM slots and reinstall your 2.5GHz CPU cards. Even if the logic board was pulled from a 2.0Ghz model then the system bus will bump up to accommodate the CPU cards. I understand this is a unique factor of the G5 design where the CPU cards can control the system bus speed.

Any time you change processors (including swapping the config around), you will need to recalibrate the temperature sensors using the ASD disc or else the fans will operate at constant full speed.

 

[Session18]

I agree with trying @Hrududu ‘s idea of swapping the processors around to pinpoint the failure.

On your Dual Processor G5, each Processor Card holds a single CPU, so you want to try isolating the CPUs to determine what is faulty.

My understanding of the G5s is that the top processor socket must have a working CPU card in order to boot, so with this mind;

1. First up, use a marker to label your CPUs with A (top) and B (bottom).
2. We are expecting slot A on the logic board to be working or else the G5 won’t POST. So, confirm this by removing CPU B from the bottom socket and booting it up.
3. Shut down and remove CPU A from the top slot.
4. Install CPU B into the top slot and boot - if it POSTs okay at this point then we know both CPU cards are okay.
5. For fun, shut down and try reinstalling CPU A into the bottom slot (swapping the original config). Boot up and see if you still only have 1 CPU active or possibly 2.

This process will determine that the fault is not with your CPU cards and points to a logic board fault as per @pl1984 ‘s reply.

If this is the case, you should be able to source any of the PowerMac7,3 boards which utilize 8 RAM slots and reinstall your 2.5GHz CPU cards. Even if the logic board was pulled from a 2.0Ghz model then the system bus will bump up to accommodate the CPU cards. I understand this is a unique factor of the G5 design where the CPU cards can control the system bus speed.

Any time you change processors (including swapping the config around), you will need to recalibrate the temperature sensors using the ASD disc or else the fans will operate at constant full speed.

[doublepost=1539322133][/doublepost]Thanks Again For The Help!

I definitely have to figure this out and will try swapping the CPU's, as suggested. Question...It's not a problem installing the processor back in in the machine with only one of the CPU's on it?

I want to make sure I understand you right, I need to run this disc every time I put this Processor back into the machine correct? and also is there a certain way to run the ASD 2.5.8 Disc once I boot up?

 

[ctmpkmlec4]

IIRC, ASD needs to be run anytime there is a CPU change, or more specifically, you need to run thermal calibration from the ASD disc anytime you make a change to the CPU configuration, even if just switching the around in the logic board sockets. I don't think you'll hurt anything running just one CPU, but don't try "hot swapping" parts. I almost suspect it's a bad socket on the logic board.

 

[Session18]

Thanks for the reply!
Would you suggest reverse the CPU's on the processor, to see if it is a bad socket on the logic board?

 

[AphoticD]

Thanks for the reply!
Would you suggest reverse the CPU's on the processor, to see if it is a bad socket on the logic board?

Yes.