Watercooling help - high pitched whine from pump

Feb 5, 2019
Just finished building a new loop using one of the custom Bitspower Sedna radiator/pump combos for the Lian-Li Dynamic. Everything works great as far as I can tell, except for a high pitched whine coming from the pump.
-It's been connected to both the pump header on a maximus XI hero Wifi, and a molex adaptor direct to the PSU - same noise regardless.
-It's not a PWM control pump, its 100% or nothing apparently. I've actually tried controlling it through software and it just shuts off at about 73%. Between 73% and 80% it will just turn on for a bit, turn off and back on. Above 80% it is full speed.
-It was making this noise with both distilled water and the distilled/mayhem dye combo in the video -It's been running 60+ hours and the sound hasn't gone away.


Jul 25, 2017
Hi and welcome to Tomshardware.

Did not see your post before now so sorry for a late reply :)

The reason you have that high pitch sound is because it is an DDC pump and not an D5.
DDC`s when they run at 100% will make that sound so all is normal. (40db - 45db range)

That is also one of the reasons people tend to go for PWM D5 pumps since they are more silent, normaly last longer and dont produce as mutch heat as a DDC.

DDC is great if you build a HUGE waterloop with alot of tight bends, blocks, etc etc, since the DDC has more head pressure than the D5 but the D5 has more waterflow.

Hope this gave you an answer :)

Got to ask since you did write: "It was making this noise with both distilled water and the distilled/mayhem dye combo"

Now my question is are you using any algae inhibitor and anti corrosion? Cause running just plan destilled water + dye = 99% sure you will get problems down the road :)
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