Mac pro fan problems?

[Johs1983]

I have a Mac Pro 1.1 that I upgraded from 2.66GHz dualcore processors to 2x 5365 3 GHz quadcore processors. I flashed the firmware to Mac Pro 2.1 as well.

The problem is that the fans now run at full speed (2700 rpm and reporting constantky 128 degress Celcius from startup). And I have no control of the speed through SMC fan control either.

Any suggestions how to solve the issue?

 

[pigoo3]

I don't believe that the cpu upgrade is the problem. More than likely it's was the Mac Pro 2,1 firmware flash. Or…did you install any other hardware such as a non-standard video card?

Did you do the cpu upgrade first…then use the computer for a while…then did the firmware flash? Or did you do the cpu upgrade and the firmware flash at exactly the same time (one immediately after the other)?

- Nick

 

[Johs1983]

Hi Nick.

Thanks for your reply. The fan problem was there already before I did the firmware upgrade to 2.1, so I don't think the firmware is the problem.

I did the CPU upgrade and didn't use the computer for a while after that (but I did test it and the fans where on full speed then). After a couple of weeks I did the firmware flash, which didn't change the fan problem.

I just discovered one more thing: I downloaded the iStat pro that can measure cpu tempereture and it says CPU A is 126 degrees C and CPU B is only 30 degrees (which I suppose is the normal temperature).

So it seems that something is wrong with CPU A... or that it is unable to measure the actual temperature for some reason!?

PS. The graphic card is a Radeon HD 4870, and besides that no video or pci cards are installed.

 

[pigoo3]

Thanks for all the additional info…and the timing of things/upgrades…that really helps.

So it sounds like the fan problems started AFTER the cpu upgrade…and already existed before the firmware upgrade. This would certainly indicate that something to do with the cpu upgrade is causing the issue.

Many times…hardware issues of this sort do cause high fan symptoms.

I should ask…did the fan problem exist BEFORE the cpu upgrade? If not…as you mentioned with the iStat temp numbers…the one cpu does sound like something is wrong…since it's temp is so high. I check the temps of my Mac Pro 1,1 fairly frequently…and in a room that is about 68°F (~20°C)…the cpu temps are about 86-88°F (~30-31°C). So a temp of 126°C is very high.

All I can suggest is…reinstall the original cpu's…and see if the fan issue goes away. But…I'm not 100% sure if the Mac Pro 2,1 firmware update will allow the computer to operate properly with the original cpu's.

And I guess I should mention. Any chance at all the something was forgotten during the cpu upgrade install? For example…did you remember to plug in each of the temp sensor cables to the logic board from each of the heatsinks?

- Nick

 

[harryb2448]

You did use Arctic Silver when you seated the CPUs I take it, and did you remove the front fan, give it a good clean and oil whilst you had it out? They collect heaps of dust the front fan, directly in front of the CPUs, and can get noisy and fast. At 2700rpm surprised you can even hear the fan if it is in good condition,

 

[Johs1983]

BUMMER:

Thank you Nick and Harry. As I run through all the possibillities I actually discovered I forgot to plug in the temperature censor cable to to the logic board from the heatsink of CPU A :O Thats what happens. But anyway I learned a great deal through all the research. And thanks for your suggestions. My mac is running smoothly now with temperatures around 30-35 C on both CPU's... nice

 

[pigoo3]

As I run through all the possibillities I actually discovered I forgot to plug in the temperature censor cable to to the logic board from the heatsink of CPU A.

I hope that you saw that I mentioned that in my last post.

Congrats on getting things fully operational…and that no harm was done!

- Nick

p.s. BTW…what Mac Pro 2,1 firmware update did you use?

 

[Johs1983]

And I guess I should mention. Any chance at all the something was forgotten during the cpu upgrade install? For example…did you remember to plug in each of the temp sensor cables to the logic board from each of the heatsinks?

- Nick

Yes, I saw that. It was because you mentioned it that I thought I should check one extra time Typical mistake ;P

And thanks, it's still running smootly. And no harm was done. Amazing how you can put new life into an old machine. Now I think I will start looking into an SSD hard drive as well.

BTW I used this firmware upgrade: Mac Pro 2006-2007 Firmware Tool Released
(someone did an edit of the main firmware upgrade suitable for Boot ROM version MP11.005D.B00). Otherwise you can use the other one I guess: Mac Pro 2006-2007 Firmware Tool Released

 

[pigoo3]

Yes, I saw that. It was because you mentioned it that I thought I should check one extra time

Ok…good deal. Either way…great that the problem was solved relatively easily.

BTW I used this firmware upgrade: Mac Pro 2006-2007 Firmware Tool Released
(someone did an edit of the main firmware upgrade suitable for Boot ROM version MP11.005D.B00). Otherwise you can use the other one I guess: Mac Pro 2006-2007 Firmware Tool Released

Thanks for the links.

One other question. Have you run any benchmark test yet on it. Maybe you could run Geekbench and let us know how it scores. I recently did the same upgrade you did (4-core to 8-core upgrade on a Mac Pro 1,1)…but I used the x5355 2.66ghz cpu's instead of the x5365 3.0ghz cpu's.

Here's the link for Geekbench:

Geekbench 3 - Cross-Platform Processor Benchmark

- Nick

 

[harryb2448]

Yes that leaving the CPU "A" sensor unplugged is enough to move a Jumbo Jet.