CPU load and fan speed change all the time

[wunay]

Hi,
I am new to FAH and the client. I am running the newest version 7.6.13 on Windows 10 with an Intel Core i7-2600 (4 physical cores + hyperthreading) + GPU (Radeon). I noticed that fan speed is changing constantly, which is really annoying. The problem is that CPU load is not constant, but changes from ~85% to ~40% every few seconds. Setting the number of threads to 4 or 8 manually did not make any difference, neither did changing the power slider to "medium" or "full". What can I do?
Thanks for your help.

[JimboPalmer]

http://www.almico.com/sfdownload.php
may help

[bruce]

FAH attempts to allocate all unused resources to itself at a very low priority. That assumes there are unused resources, which is often true. What else is running on your computer when the fan speed is varying?

Please post your log. See below.

[uyaem]

I've had the same thing happening on Ryzen 3900X, and solved it by using the "Ryzen Master" application to limit the clock speed to 3800 (base clock).
This puts a constant load on the CPU, rather than it trying to boost all the time, and therefore the fans stay at the same speed (=changing slowly if necessary).

Maybe the same can be done for Intel, using Intel specific tools. However, I used to run an i7-2600K with stock cooler and never had these issues there.

[MeeLee]

Go into your bios.
Most UEFI bioses have a fan curve entry, where you can adjust the fan ramping up speed.
If I'm using my CPU for folding, I use the following setting:

Temp : Fan speed
<50C : 20% (on some motherboards this is the minimum. Some fans experience failures due to too low voltage, when fans don't have sufficient voltage to self-start. For that reason, I personally put the minimum fan speed to 20%. This equals ~0.25W of power usage.
50-65C : 33%
65-75C : 50%
75-85C : 75%
85-95C ; 100%

If you want a more aggressive fan curve (you are ok with more noise),
<50C : 33%
50-65C : 50%
65-75C : 75%
75-80C : 100%

You can check CPU temperatures while folding, and depending on your setup, can lower CPU temperatures while folding, by adjusting the fan curve that matches those temperatures.
Eg: if you're folding at 100% CPU utilization, and your CPU temperature reaches 75C, you can increase the fan curve from 65-75C to a higher fan speed, in order to get lower CPU temperatures.

In some cases, you can be folding with a low fan curve, and the CPU barely hits 55C. In such case you can easily lower the fan curve, to get even less noise.

You will want to aim for ~65C temperatures, but anything from 55-75C is acceptable for most CPUs.

You can also adjust fan curves to have more temperature measurements, so your fan will ramp up more gradually, like so:
<50C : 20%
50-55C: 25%
55-60C: 33%
60-65C: 50%
65-70C: 66%
70-75C: 75%
75-80C: 99%
>80C: 100%

This way, your fans will ramp up more gradually.

You can also record where fan noise becomes obnoxious; eg: your CPU fan starts becoming loud at say 80%.
Then try to match your CPU operating temperatures to remain under that 80% fan speed.
That way, the fan will give you maximum cooling for minimum noise levels.

There are many approaches, and it becomes even more interesting when you include large fluctuations in ambient temperatures.

[jrweiss]

Added to what MeeLee said, some UEFIs also allow you to set a delay in fan response. I would not set a delay for increasing, but set a long delay for decreasing.