How do I use Fan Control on a MacPro with nVidia?

[Mac Hammer Fan]

I have a Geforce 980 installed in slot 1 in my Mac Pro 4,1>5,1 with 32 GB RAM.
https://www.amazon.de/EVGA-GeForce-GTX-04G-P4-2983-KR-Superclocked/dp/B00O3JZAYA
The other slots contain a GT 120, a PCI-e USB 3.0 card and a PCI-e card with a Samsung SSD.
Occasionally the fan speed increases without reason from 800 rpm to 2000 what makes my Mac Pro very noisy.
I have installed Mac Fan Control but I don't know how to use it.
Can someone give me advice about the settings needed to reduce the fan speed under normal circumstances?
TIA

 

[mikas]

At first you could try the trick from the older threads of the forum:
Run a grapfics card 3D intensive app for a minute or so, and after that quit the application.
Your fans should settle down now, and be so until restart. They will propel up again after next start up, so just run the trick app again. Of course the card fans and PCIe fans ramp up again if I do some heavy lifting with them, but that's only normal behavior. The "no load situation" of fan behavior is fixed though.

This trick has worked for me. You could automate the procedure with some scripting, but I haven't bothered. I don't shut down my Macs so often, so I can manage the manual way.

I believe the of this forum gurus saying that it is a bug in Mac Pro SMC (system management control) software.

I've got Mac's Fan Control still in use, because I want to see what's happening. And sometimes when I am rendering for hours or days, I want to get some extra cooling to keep my X5680 Xeon's under 78,5 °C. Just use the custom controllers for fan speed according to appropriate sensor readings. You can try experimenting with the sensor value range. Do not use too narrow of a temperature range, because it can give a upp and down pumping fan behavior.

I've got a RX 570 and GTX 1060 in use. Trick works with both of them.

 

[Mac Hammer Fan]

If I choose, sensor based value on pcie-slot 2, which minimum and maximum temperatures are recommended?

 

[mikas]

My Mac Pro's are at a different address than me right now. But I think some helpfull person will chime in.

 

[h9826790]

If I choose, sensor based value on pcie-slot 2, which minimum and maximum temperatures are recommended?

If you want to avoid abnormal high fan RPM by using MacsFanControl. You may

1) set your PCIe fan base on PCIe ambient, e.g. min 38, max 58

2) set your PSU temperature base on PSU 2 temperature (some version call it PSU component temperature), also min 38 max 58 is a pretty good number to start with.

If your ambient temperature is low, or you want to further lower the temperature a bit, you can simply lower the min temperature

 

[mikas]

I think a lot depends in what kind of a surrounding your machine resides. For example we got some minus degrees outside today, and my room temperature is definetily not over 20 degrees celsius. You would have to configure your rig differently in some place like near equator etc.

But my current fan settings can be read from attachment pic. All 6 cores do cinerender. I have adjusted the exhaust and intake fans similarly to each other, and now CPU diode keeps at 66. I will have to losen it a little bit, there's too much noise now.

It's been speculated before that Macs Fan Control gives a wrong number for CPU A (B) from PCECI. It seems so, it should be declining under heavy load, not increasing. But I am not sure.

 

[Mac Hammer Fan]

Thanks for your useful advice.

 

[martyr]

I think a lot depends in what kind of a surrounding your machine resides. For example we got some minus degrees outside today, and my room temperature is definetily not over 20 degrees celsius. You would have to configure your rig differently in some place like near equator etc.

But my current fan settings can be read from attachment pic. All 6 cores do cinerender. I have adjusted the exhaust and intake fans similarly to each other, and now CPU diode keeps at 66. I will have to losen it a little bit, there's too much noise now.

It's been speculated before that Macs Fan Control gives a wrong number for CPU A (B) from PCECI. It seems so, it should be declining under heavy load, not increasing. But I am not sure.

I agree. the "CPU A/B core from PCECI" is inverted, meaning that 100 is actually 0.

If you look at iStats Menus you'll see a better idea of how far away you are to the ProcHot value, which is inversely correlated with the "CPU A/B core from PCECI" value:

https://i.imgur.com/aYgBMoj.png