Trying to correctly run a 3pin cpu fan off my Asus p5b mobo 4 pin cpufan header and have it use all the ASUS Q-fan features. From what Ive gathered the 4 wires are earth, permanent 12v, speed(rpm) sense wire and a pwm control wire. (not in that order) Correct me if Im wrong but I think the PWM wire from the MOBO carrys some varying signal that is used by the fan to control its pwm circuit inside a special fan.(that has a PMW circuit inside it). It is either a trigger pulse or a varying DC signal, neither of which can directly run a fan. These require special fan like the CNPS9500AT, not the majority of after market quiet fans that are 3 pin 12v, earth and speed sense. Someone must have the circuit for taking that control signal and turning it into a varying supply to control the speed of a 3 pin fan. (PWM or linear) The problem then if you use PWM it will play havoc with the speed sense, so will the mobo still need a speed sense signal to correctly control the cpu fan speed dynamiclly with cpu temperature? If so can you patch into the speed sense circuitry of a fan to supply it permanent 12v so fan gives out correct speed sense signal?