ASRock CPU Fan header ramps up from boot?

iamholam · 5 May 2016 at 13:33

Posted this on motherboard forum but it's more of a cooling question. I have an ASRock Z170m Pro4s motherboard and have noticed that the CPU cooler ramps up in speed from startup. When it first boots the fan spins quite slowly before speeding up.

Not much of an issue except my stock Intel cooler seems to stick at the "startup" phase and doesn't spin until I give it a prod.

Is this standard functionality on motherboards for the CPU header?

andicole0 · 5 May 2016 at 13:38

There are a number of fan speed profiles in the bios.
Andi.

iamholam · 5 May 2016 at 13:53

Think I will need to read the manual a bit better but it doesn't seem to be speed profile as a prod on the fan will kick it into life. Even though the Intel cooler is a four pin connector no matter which profile I set it to the fans remain the same speed.

Tealc · 6 May 2016 at 12:39

Make sure the fan control option is set to PWM. A DC controlled fan may not start up if the lower threshold voltage is set too low eg 7v, whilst if PWM is set at as little as 30% (effective 3.6v) the fan would start right up. Also the PWM controller of most boards should start all PWM fans with a burst of 100% for a few seconds while the system boots.