CPU fan not throttling all the way down on a Supermicro A2SDi-4C-HLN4F motherboard?
Is pfSense in anyway controlling the fans on Supermicro motherboards?
I have a A2SDi-4C-HLN4F based system installed in a place that has wide variation in ambient temperatures. The CPU fan that I installed myself is Everflow 60x60x10mm PWM 4-pin which is very quiet once the system is done booting/rebooting. (It is the only fan in the system.)
The system will stay very quiet until the first time the ambient temperature goes up. Then the fan spins up and becomes quite loud. As the ambient temperature cools down, the fan spins down but never all the way down to its initial quiet state.
Is there a way to fix this?
That's all down to how the fan controller is configured. pfSense has nothing to do with that.
Check what settings you have available in the BIOS. You might be able to improve the controller settings there but unfortunately only a few values are usually exposed.
Look for some cute scripts in the ixsystems community, search for