• I have been using my pfSense with my Supermicro A2SDI-4C-HLN4F-O motherboard. I finally moved to another case due to noise from the supermicro 1u chassis. I am using a Noctua A12 case fan above the cpu for cooling. The fan just turns on and off constantly. I am wondering how to control the fan?

    Also, I am just using the main 12v power on the motherboard with a 60w power supply from Supermicro. I am hoping I do not have a power issue. Any suggestion?

    I do need to update the software, which I will do in a bit.

  • Netgate Administrator

    Beyond poking the registers on the SIO chip directly the only interface to configure the fan controller is usually in the BIOS setup.
    The fan starting and stopping may not be a power problem. There are could be a number of settings in the controller that might cause that.


  • The fan turns on normal, and start the on off session after complete boot up. I will look at the bios for sure.

  • That board has an OOB/IPMI NIC right?

    i think what you're looking for is the fan speed alarm threshold(s) in the IPMI/BMC webUI, not the BIOS. the noctua fan probably spins slower than what the "low" RPM threshold is set for. this will set an alarm condition. the BMC tries to resolve the condition by running the fan at full throttle. once it does, and the fan spins up, the alarm condition clears. when the condition clears it returns the fan to "normal" operating state, dropping the fan under the low threshold again. at that point, it starts the whole alarm loop again, hence the cyclical speed up, speed down, speed up, speed down stuff that you see.

    i hope that helps....maybe?

  • @cjohnson

    This sounds about right. I set the fan profile to full at all times. The only profile to work. I am not see a spot to change speed settings. I used a resistor cable to step down the fan speed.

    I might have to change the fan to another brand.

  • I'm not certain exactly how, or even if this would apply to your board but, i've done something like this with linux on X9/10/11 boards in the past.


    essentially, you set something like a "full speed" mode in the BMC which then allows you to have a little more control (externally of the BMC, via the OS) over what the fans are doing and/or stopping the BMC getting in your way. on the other hand (shrugs), it might be that the K.I.S.S approach with the current limiting resistor idea that you've implemented is better for you.

  • @cjohnson

    I would not mine the ability to control the fan speed via software. This allows me to tune it. I will give it a shot, since I had to use ipmi tool to recovery the password.