I have an ROG Strix X570-E Gaming motherboard, with a DC case fan plugged into the M.2_FAN header on the motherboard. It is running the latest (v3001 right now) BIOS.

Since this is a noisy stock 120mm fan, and I have plenty of other cooling, I would like it to be off until it's really needed. I have configured it as follows:





With the fan curve:



So I would expect the fan to be off most of the time. One thing I notice is that there isn't an explicit "Enable fan off" checkbox for this fan, which there is for the other DC case fan plugged into CHA1_FAN.

When I power on the machine (or suspend+resume), the fan is set to full speed:



It stays at this speed, until I click on the fan curve tab in the BIOS, then it powers down, as expected:



So I can get the effect I want if I boot into the BIOS every time I turn on my machine... Not ideal!

I believe this is a bug - is there something I'm missing?

Thanks 🙂