Noisy AIO

Hi all,

I built a system recently with a Hydroshift II 360C AIO and finding the pump ramping up and down as I can hear the whining sound.

My PC is generally very silent based on manual fan curves, and I've tried setting both the AIO pump speed to 80% constant in both BIOS and Gigabyte Control Center software (using it for RGB control...). The AIO pump is connected to my motherboards "CPU Fan" header.

I can hear the pump rev up and down intermittently and I've confirmed it's the AIO by basically putting my finger on the block to feel the vibration and watching the RPM fluctuate between 800 – 2300rpm, whilst coinciding with the sound.

Any idea what's causing this? Could this be a defective AIO?

CPU and PC is running cool and stable otherwise. No overclocking, stock 9900X on a X870 motherboard.

THank you

Got a pump header mate? Should just give you static control on that one, without PWM.
A 'CPU Fan' header generally expects to be ramping up and down controlling a fan, not a pump.
It sucks when the pump is the noisiest bit, but static speed control is the answer. You don't need your pump speed ramping like your fans - it just needs to circulate the coolant.

Yeah, motherboard has a few pump headers, just connected it to CPU Fan header due to proximity for cable management... Though I've got the fan speed set to 80% in both BIOS and Gigabyte's windows software... would still ramp?

I could try the pump header see if it makes any difference

It might just give you the option of no control. It's weird that your Fan header allows static control but still seems to ramp. I've found on some Gigabyte boards they need to have the fan profile set to 'full speed' before static control will work, and on others the static control seems to override the profile - but it is inconsistent and even changes across BIOS revisions.

Likely an air bubble. This sounds ridiculous, but if you can take out the radiator and give it a helluva shake (bonus points if you do this while its running) that can be enough to get the bubble to move on.

you shouldnt really be able to hear the pump rev up or down in normal operation, with a decent AIO (I have used many!).