How fast should my liquid CPU cooler pump be running (Cooler Master Masterliquid)

[daszani]

I have the pump plugged into my Chasis Fan slot on my mobo. In the bios, it says the "fan" is running at 1600 RPM. I currently don't have an adapter to plug the pump into my PSU. Should I be controlling how fast the pump runs?

Also, on the radiator itself, there are two fans. Would it be a big deal if I were to remove one fan? (I'm using an NZXT s340 case, and because of the second fan, the pipes can't fit into the central metal cable manager. While not really that big of a deal, since my CPU runs at 40c when gaming, I was wondering if I should remove one of the fans)

 

[zoltan.boese]

Unless it is loud let it run at full speed. The pumps wheel is tiny, it often runs at 3-4x the speed of the case fans.

As for the radiator fans: keep them around 1000-1200rpm for silent running and rump them up if your cpu temperature goes above 60°C!
If it is a 120mm radiator you can remove one fan without further ado. Otherwise make a test run with on fan. Nothing can go wrong, but if you are not satisfied with the cooling capacity mount the radiator to the top!

 

[zoltan.boese]

Also [video="https://www.youtube.com/watch?v=xNAMxZgvves"][/video]

 

[daszani]

Thanks for the reply! One more thing, should the pump (4 pin) be running on PWM or DC? I was under the impression that if it had 4 pins, it should be run on PWM. However, when I switch from DC to PWM, the LED on the pump brightens significantly and the I can hear a bubbling/flowing sound from the liquid, even if I turn it down to the minimum 20%.

 

[Karadjgne]

Unless specified as a variable speed pump (common on fractal design and nzxt Kraken), you should run aio pumps at full 12v. This generally means the pump rpm will be anywhere from @1200rpm to almost 4000rpm depending on the pump, so 1600rpm sounds about right. You should also take note of the wiring, the connector means nothing but placement, depending on the aio, the pump could have 2 wires or 3 wires. It'll run DC analog voltage. Most of the larger or higher end designs use Sata power for the actual pump/fans power needs, directly from the psu, they'll use only the tach/ground wires from the motherboard header, just to read pump rpm and to satisfy motherboard needs for cpu_fan header population. Cheaper/smaller aios will run 3 wire and draw power for the pump from the mobo header. So you will see 4pin connectors, but have only 2-3 wires. None use pwm as that's a switched source, continuously turning the pump on and off. This'll cause sound in the pump as back pressure takes longer to roll around the tubing/radiator than the on/off cycle of the pwm. In bios, whatever header the pump is using (if it's header powered) should have any q-fan or other eco settings disabled and duty cycle set at permanent 100%. Fans, run as you please, but with aio pump flow as characteristically low as it is, full speed is recommended.