Zero RPM is on by default. I don't know if it doesn't work with VBIOS or there is a bug in Radeon Software. My fans won't start at any temperature. I managed to over come this by using manual settings. But: I can't set fan speed below 42 %. This limit comes from VBIOS? I have seen screen shot of 19.12.X software with fan speed set to 0 % at certain temperatures. This might have been issue since 20.1.1 but I rarely game so I haven't spotted this fault earlier.