asus p6t deluxe cpu fan speed fixed?

[QuantumPion]

So I just started trying to OC my core i7 on an asus p6t deluxe. I just noticed while trying to turn on the cpu fan automatic speed control in the bios that the fan RPM remains constant at 1500 rpm regardless of the setting. When I try using the bundled software application, the cpu fan will still not change speed.

I am using a TRUE 120 heatsink with the included fan, which is a 120 mm 3-pin fan connected directly to the motherboard header. Is there some reason why this fan or the motherboard can't change the fan RPM?

 

[PCTC2]

The CPU fan is a PWM 4-pin header, and can only control PWM fans. I don't know if there's a BIOS option to change this...

 

[QuantumPion]

Ah...so it is. O_O