Just looking into getting a fan controller and maybe some replacement fans for my machine so I can play with some overclocking - however I am confused over PWM and fan controllers. I assume the majority of fan controllers vary the voltage which non PWM fans use to vary the speeds - so are all the fans listed on OC non PWM unless specified? and how do I know if my case fans are PWM or not - they are all 4 pin in I think an Antec 1200 case (bought it as a system a couple of years back)
PWM Fans
- Thread starter jimjamuk
- Start date
There are two types of 4 pin fans.
Molex - a big 4 pin that connects up to your PSU, just like Antec Tri-cools.
4 pin PWM - a small header type connector with 4 wires, of which 2 are power, 1 is rpm feedback and the last one is for PWM which is a 25kHz signal that tells the fan to switch on and off 25000 times a second.
The other type is 3 pin which are again the small header but with no PWM signal do these must be controlled by varying the voltage or some other means.
Fan controllers are normally only 3 pin compatible and rarely 4 pin PWM compatible and basically never Molex compatible. A PWM fan hooked up to a 3 pin fan controller will work, mostly, but you lose the PWM feature, which at the end of the day is silly as you've paid extra for the PWM electronics an hooked it up to a variable voltage source.
I've created a circuit that can run 3 pin fans off the motherboard PWM to give the best of both worlds, check my signature for the development log.
Molex - a big 4 pin that connects up to your PSU, just like Antec Tri-cools.
4 pin PWM - a small header type connector with 4 wires, of which 2 are power, 1 is rpm feedback and the last one is for PWM which is a 25kHz signal that tells the fan to switch on and off 25000 times a second.
The other type is 3 pin which are again the small header but with no PWM signal do these must be controlled by varying the voltage or some other means.
Fan controllers are normally only 3 pin compatible and rarely 4 pin PWM compatible and basically never Molex compatible. A PWM fan hooked up to a 3 pin fan controller will work, mostly, but you lose the PWM feature, which at the end of the day is silly as you've paid extra for the PWM electronics an hooked it up to a variable voltage source.
I've created a circuit that can run 3 pin fans off the motherboard PWM to give the best of both worlds, check my signature for the development log.
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Just check your motherboard first most have fan voltage settings or make your own 12v 7v 5v cables even.I still think fan controllers aren't really needed unless you want it sounding like a hoover when gaming and quiet when not I just prefer to achieve my level of desired quietness and leave it at that like I have all 4 fan headers on my board set to 75% aka 7v in the bios setting and the others I run direct to psu via 5v adapter cables.