H50 with P5Q, PWM?

[HBAndrew]

Hi guys, I just bought myself a Corsair H50 CPU water cooler, and instructions say to plug the pump into any fan connector, however I remember someone on here from OcUK HQ mentioning how most of the H50's returned to be faulty was because the pump was connected to PWM (not sure if this means they were then damaged or just worked fine but didn't get enough power).

I have the Asus P5Q mobo, and as far as I can tell, all the fan connections use PWM? The fan on the rad has to go into cpu_fan, where do I plug the pump?

Do I have to disable PWM somehow? Or is there a way to only disable PWM on one connector? Or is it best to disable PWM completely and then use speedfan or something to control the mobo connected fans that way?

I also have what seems to be a convertor from 4 pin molex to 3 pin fan, where only 2 of the pins are connected, one to red and one to black, I assume that means anything connected to this would get full power? Or would it not be wise to plug the pump into this?

Thanks for any help

 

[cmndr_andi]

Hi there.

You are correct that if you plug the pump into a motherboard fan header it can be a problem. When using a 3 pin connection (like the pump or standard fans) the voltage output is controlled by the board - since the pump needs to be supplied with the maximum of 12V at all times this can be a problem.

This can be remedied by turning off motherboard fan control in the BIOS. However, if you do have a 4 pin molex to 3 pin fan adapter (2 pins connected is fine) then I strongly suggest just using this, as it will give the pump exactly what it needs and you can control fan speeds on your mobo - it also means you don't have to mess around in the BIOS as much.

 

[setter]

Another fan connector on the p5q that you can use is the PWR fan header. This fan header doesnt utilise any fan speed control, therefore anything connected to it will run at full speed all the time. This would save you from having to use a molex adapter meaning one less cable in your case.

 

[HBAndrew]

Thank you, PWR seems to be working fine, speedfan says CPU0 is around 1700rpm, dropped temps from 45c idle to 18c, and 60c load to 30-33c, amazing. Time to push it as far as I can.