HSF... 3/4pin difference?

[seriouscat]

Using a Thermalright Ultra Extreme with a 120mm fan thats 3pin. Just wondering if a 3 or 4pin fan makes a difference to the mobo and how it controls the fan?

Would the mobo control the speed of a 3pin fan?

Also, does speed control not matter with 120mm cpu fans since they are quieter anyway when compared to stock?

Lastly, since I use a 3pin fan, does it matter if I connect it to the CPU fan or Chassis Fan connectors on my mobo?

 

[Arcanedeath]

4 pin fans are pwm fans that the cpu header can control, 3 pin fans require voltage adjustments to control them or a different form of fan control, some motherboard don't play nice if you don't have the CPU fan connected so It would be a good idea to just use it even w/ a 3 pin fan and not use the chassis fan instead.

 

[seriouscat]

Originally posted by: Arcanedeath
4 pin fans are pwm fans that the cpu header can control, 3 pin fans require voltage adjustments to control them or a different form of fan control, some motherboard don't play nice if you don't have the CPU fan connected so It would be a good idea to just use it even w/ a 3 pin fan and not use the chassis fan instead.

Cheers. Is there a disadvantage with PWM vs Voltage Adjustment Fans?

Anyone know of any recommendations of a 4pin 120mm x120mm x 25mm PWM fan for the TRUE cooler?

(non-overclocked Q9540)

Cheers.

 

[Arcanedeath]

I'd suggest a sythe Sflex E 1200 rpm fan, its 3 pin but you can just run it at full blast and not have to worry about having it adjust

 

[Zepper]

Most mobos can adjust the CPU fan (must be connected to the CPU_Fan header) in a few steps if voltage control (3-pin) or over a range with a PWM fan (4-pin). They should also support the voltage control of a few step for a 3-pin fan connected to a 4-pin CPU_Fan header. In general you need to have a fan connected to the CPU_Fan header that has a working speed sensor as most mobos these days have a CPU protection system (perhaps mostly AMD CPU mobos) that will not boot if they don't detect a working CPU fan (via the speed sensor lead). To boot after a boot failure, you have to clear the CMOS. Once you get a good boot on these mobos, you can often disable the CPU protection in the BIOS setup if you want to - I never do unless I choose to control the CPU fan myself which I am doing right now with my fan controller.

.bh.