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Plugging a liquid CPU cooler directly into PSU

Hey guys,

I just finished a new build, and everything is running smoothly. However, there remains one difficulty. I used a mini-ITX board, (Gigabyte Z87-N WiFi) and it only has plugs for two fans, the CPU fan and one system fan. My computer is relatively powerful and heating was a concern, so I wanted to use at least two case fans. I ended up plugging both the rear fan and the liquid cpu cooler (Corsair H55) into the same plug with a 3-pin splitter, while the front fan takes the 4-pin fan outlet.

The problem is that because I am using a 3-pin splitter, the motherboard cannot regulate the fan speed, and as a result my rear fan is going 100% all the time. It isn't deafeaning or anything, but it is noticeable and distracting, and makes me feel like my computer is working too hard all the time.

The solution I came up with is to plug the CPU cooler directly into the PSU with an adapter, to plug the rear fan into the CPU fan slot, and the front fan into the system fan slot. It's a little weird, but it in theory would allow the two case fans to be regulated by the motherboard and thus not go full blast at all times, while the CPU cooler would go full power, but be very quiet as it is a liquid cooler.

Is there any reason not to do this? Any reason to worry about damaging anything?

Thanks!
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  1. Best answer
    As long as you have the liq cooler pump connected to a +12V (non-controlled) source, you are fine. You don't want to use a fan header for the pump that can be regulated as to its voltage or PWM.

    If you have your rear 3 wire fan connected to the 4 pin PWM CPU FAN header, I don't see how that can control the RPM of the fan. That header only has PWM speed control that sense the CPU temp. It doesn't have voltage control as far as I am aware. And a 3 wire fan has no PWM ability.
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