SpeedFan has no effect

[rickyk586]

My CPU fan always runs at about 4100 RPM. It is 3 pin, so I was hoping that SpeedFan could allow me to adjust the voltage to slow it down, but I can't seem to figure it out.

I have tried setting AMD Cool'n'Quiet in the BIOS to both enabled and disabled, but that does not have an effect. In SpeedFan I went to advanced and selected F71878A, set all 3 PWM modes to "Manual set RPM", and all 3 PWM Types to "Linear DC mode". I also tried setting all 3 PWM Types to "PWM mode (3-wire). I can't get the fan to change speeds at all.

The fan goes right to 4100 RPM from a cold start, and the temp never goes above 45C. Any help is much appreciated!

 

[Faux_Grey]

I'd suggest plugging a 3-pin CPU fan into a sys_fan header and try from there.

CPU_fan headers usually only work through 4-pin pwm, while sys_fan headers control via voltage, which is the only way to ajust a 3-pin fan.

 

[Shaun o]

The pin header on your motherboard for the cpu fan should be four pin.
The fan it`s self needs to have a four wire, and pin arrangement for PWM via the motherboard bios to control the set fan power and profile speed.

A three pin arrangement can be found on fans that are in the 120mm to 140mm size in diameter.
Used as case fans.

And on the motherboard you have can also be a mixture of three, or four pins connection.
Three being more common for case fan motherboard headers.

Put simply if the cooler is not one supplied by the cpu maker such as Intel or AMD then and three wires only it more likely a fix speed fan from 800 rpm to 1200 rpm.
Or is fitted to an after market cpu cooler that is quiet cheap in price to buy as an aftermarket cooler.

 

[rickyk586]

I ended up just ordering a 4-pin fan for $10. I figured if it has it why not use it...