Classic Mac Pro normal temperature questions.

[William Payne]

The other night we had a really hot humid night and for some random out of the blue reason my fans started running faster then normal, mainly the PCIE fan and the PS fan Instead of running at idle speed where everything normally runs they ran about twice as fast not full speed though. They would spool up then get to an rpm drop a bit then spool up again and repeat. When I checked temps in macs fan control all the temps seemed fine, I keep macs fan control on auto if that means anything. I wound up just turning the machine off and going to bed as it was a very hot humid evening.

The next morning it was still doing it but after running Unigine Heaven they corrected themselves and the fans operated as normal from that point. The room temperature had also dropped at this point.

Just before, I had my machine unplugged and when I plugged it all back in it did it again and once again corrected itself after running the Heaven benchmark and now is normal again.

I do want to say that my machine temps never get too hot and the fans generally stay around idle most of the time, if running Heaven the fans will spool up but the fan that spools the most which is the pcie fan generally stays below 1500rpm.

I am not at all annoyed by this, I am more wondering what is going on as generally my machine never gets hot and runs fine all the time.

It would be nice if there was say a standard operating temperature chart or whatever to just have for peace of mind and check now and then.

Does anyone have any input on this?

 

[Darmok N Jalad]

I've had that happen on my cMP as well. It would just ramp up fan speeds out of the blue. I've found that if you just run a few processing intensive programs (like GPU or CPU benchmarks), it helps "normalize" the system again.

As far as temps go, most PC hardware can tolerate some pretty high load temperatures (especially GPUs). It would seem that by default, Apple tuned the fans to allow higher temps so you have quieter fans. I'm sure this is well within spec, as even my 2009 model still operates quite well after all these years. The use of heatsinks helps as it is, since they really help dissipate the heat, and even a low airflow helps keep the thermals from getting out of hand. Plus the case is quite open on front and back.

I set my fans to a more aggressive cooling scheme, but even then it takes a while to get the fans spinning.

 

[William Payne]

I've had that happen on my cMP as well. It would just ramp up fan speeds out of the blue. I've found that if you just run a few processing intensive programs (like GPU or CPU benchmarks), it helps "normalize" the system again.

As far as temps go, most PC hardware can tolerate some pretty high load temperatures (especially GPUs). It would seem that by default, Apple tuned the fans to allow higher temps so you have quieter fans. I'm sure this is well within spec, as even my 2009 model still operates quite well after all these years. The use of heatsinks helps as it is, since they really help dissipate the heat, and even a low airflow helps keep the thermals from getting out of hand. Plus the case is quite open on front and back.

I set my fans to a more aggressive cooling scheme, but even then it takes a while to get the fans spinning.

Yeah I mean there are hot summer countries that get hotter then my machine.

 

[owbp]

Does anyone have any input on this?

PCI and PS fan ramping up at cold boot is absolutely normal behavior with aftermarket graphics card in cMP. It has nothing to do with real temperatures.

Be sure to run Luxmark or CUDA-Z (or any app that will force GPU to go into 3D mode aka work a bit) for a few seconds and it will get sorted, as you have noticed. Didn't mention Unigine since it has a longer load time than other apps.

I'm sure you'll find much more elaborate answers on this topic if you search "pcie fan speed graphics" or similar, here on MR.
Just wanted to ease your concern regarding temps.

 

[William Payne]

PCI and PS fan ramping up at cold boot is absolutely normal behavior with aftermarket graphics card in cMP. It has nothing to do with real temperatures.

Be sure to run Luxmark or CUDA-Z (or any app that will force GPU to go into 3D mode aka work a bit) for a few seconds and it will get sorted, as you have noticed. Didn't mention Unigine since it has a longer load time than other apps.

I'm sure you'll find much more elaborate answers on this topic if you search "pcie fan speed graphics" or similar, here on MR.
Just wanted to ease your concern regarding temps.

AH OK!! that actually explains a lot, yeah I didn't think it was anything to worry about.