Motherboard fan connectors

[samwgreen]

Hello,

I have same Asus P8Z68 motherboard in my current build. My CPU fan 4 pin is connected to mobo. I want to have motherboard speed control the 4 fans I have. Two fans I just ordered have 4-pin so will plug into mobo. Two fans in case have 4 pin molex. What do I use to get these to plug into mobo 3-pin to control from motherboard. My case also has a fan speed control which I can use if needed. Thanks. Sam

 

[geofelt]

4 pin molex connected fans will run at full speed unless the voltage is reduced. That can be done in various ways, probably best from your case fan speed controller.

3 pin fan connectors will include a fan speed sensor, this is what is really necessary to be able to adjust the fan speed with motherboard software such as speedfan.
4 pin pwm fan connectors(smaller than molex) need to be controlled by the motherboard via pulse width modulation like the cpu fan is. It is unusual for a motherboard to include these type of 4 pin headers 3 pin is more common. If you plug a 4 pin pwm fan header into a 3 pin motherboard header, it will run at full speed.

If your fans are suitably quiet at full load, I would not bother to try to modulate them. Often the constant drone is less obtrusive than a constant change in speed.

 

[samwgreen]

Thanks. Great info!

 

[samwgreen]

Best answer selected by samwgreen.