MP 1,1-5,1 Mac Pro 4,1 ATI Radeon R9 280x Fan speed

[ruben_ruben]

Hi,
I just got an new GPU for my Mac Pro 4,1 (Firmware 5,1). It is a ATI R9 280x 3 GB. For reasons I don't know the fan runs most of the time at 1500 - 1700 rpm at a temperature of 40° Celsius (104° F). The ATI R9 280 that I used before run at approximately 900 rpm. Is there anway to control the fan speed of the GPU softwarebased (like Macs Fan Control)? Or is there anything I can do to lower the fan speed. I assume the fan runs too fast for this low temperature.

 

[h9826790]

Is there anway to control the fan speed of the GPU softwarebased (like Macs Fan Control)?

No

Anyway, from memory, there is nothing in macOS can see the 280(x) fan speed. Where you get those numbers from?

 

[ruben_ruben]

Where you get those numbers from?

I got it from an application called iStat Menus https://bjango.com/mac/istatmenus/

 

[h9826790]

It won't show the graphic card's fan speed.

 

[ruben_ruben]

You can find it under "sensors" Expansion Slots - see attached picture.

 

[KeesMacPro]

You can find it under "sensors" Expansion Slots - see attached picture.

There is no GPU fan reading in the picture .

The picture shows 5 internal fans:
-Booster1 located inside the CPU heatsink
-exhaust = exhaust processor cage
-expansion slots= PCI fan located in front of the GPU
-intake = intake processor cage
-power supply= obvious

 

[ruben_ruben]

Ok - thanks for the information. Than it is the fan "expansion slots" that is running too fast. I can deal with that with Mac Fan Control I guess.

 

[h9826790]

AirOut: A solution to the racing fan bug

Introduction The racing fan bug is a well known issue that affects certain cMP systems with upgraded video cards, particularly systems with SMC version 1.39f5. On these systems the PCI, PS, and booster fans spin abnormally fast at idle, causing unnecessary noise. Although the issue appears to...

forums.macrumors.com

 

[hwojtek]

Ok - thanks for the information. Than it is the fan "expansion slots" that is running too fast. I can deal with that with Mac Fan Control I guess.

It's not "running too fast". It rotates at a speed that is adequate for the temperature in the expansion slot area in order to compensate for your GPU heat production. Perhaps do a SMC reset first?

 

[h9826790]

It's not "running too fast". It rotates at a speed that is adequate for the temperature in the expansion slot area in order to compensate for your GPU heat production. Perhaps do a SMC reset first?

That's a known issue. The PCIe and PSU fan speed not just temperature related, but also power draw related.

SMC may misinterpret the readings from a 3rd part graphic card after boot, and command an unnecessary high PCIe and PSU fan speed (even still well within normal range) when the GPU still very cool.

It's very clear that's a bug, because we can bring the PCIe and PSU fan speed back to normal idle by stressing the GPU a bit.

If the fan spin up due to temperature, it should spin up more if we stress the GPU, but not slow down.

 

[hwojtek]

That's a known issue. The PCIe and PSU fan speed not just temperature related, but also power draw related.

OK, thanks. I stand corrected.
(BTW - this happens on my MP, strangely however, only in Windows)