Question AMD Ryzen 9 5900X high temperatures with AIO installed ?

Aug 24, 2021
I recently upgraded my PC with Ryzen 9 5900X and temps are really concerning me. Let me introduce my PC setup first:

OS: Windows 10 64bit
MOBO: Gigabyte Aorus X570 Master rev. 1.2 - BIOS F33
RAM: G.SKILL Trident Z RGB 32GB 3600Mhz CL16
GPU: Power Color RX 5700XT Red Devil
PSU: Seasonic Focus GX850W
CASE: Lian-Li O11 Dynamic with 3 x 120mm FAN on side with intake position
COOLING: Corsair H115i RGB 2x140mm mounted on top with exhaust position
THERMALPASTE: Thermal Glizzly Kyronaunt

Edit: my AIO is connect via 4pin into CPU_FAN, and fans from radiator are connected through wires that comes from pump, also there is SATA for power.

  • Idle CPU: 45-65degrees / Coolant Temp 32 ~deegres
  • Gaming overcomes 90degrees very easly / Coolant Temp rarely overcome 40deegres
Fans in AIO are set for Balance and Pump for Extreme. I heard a lot of voices that pump can be wrongly mounted, and screws (2 in my AIO) should be tighten up. Already did that, and im afraid to do it more, as mount starts to bend. I saw that pepole are runing similar setup with a lot lower temps, so whats wrong?
Last edited:


Win 10 Master
if i made a PC using that case with water cooling, I would mount the 280mm rad on side as intake and use the 3 x 120mm fans as exhaust. CPU would get the cool air from outside of the case, and the temp of the air you get from out of radiator really isn't that hot.

If CPU is getting all the hot air from the GPU fed into it then yes its going to get hot.
Reactions: MeanMachine41
Aug 24, 2021
Also i found a lot of threads about how AIO should be installed.
So right now my Pump i connected like this:
  • 4pin CPU_FAN header
  • usb cable to USB header
  • two radiator FANs are connected by 4pin headers into wires that goes to pump
  • SATA to PSU for power
Is this setup right? My MOBO have 2 SYS_FAN*_PUMP headers, and CPU_OPT header that stands for (Water Cooling CPU Fan Header )

Im also want to add 3 more 120mm fans, currently have 3x SP120mm RGB fans with LED node controller (just rgb), what extention/hub should i use if dont want use every single SYS_FAN header, as it will generate big mess in my case


The O11 Dynamic doesn't support 280mm side radiators, so that's a no-go.

Kryonaut needs to be spread over the entire IHS manually - in case you didn't do that, but it'd probably be better to not use this paste at all with a 5900X, as you won't be able to avoid more frequent repastes.
"Kryonaut uses a special structure, which halts the drying out process at temperatures of up to 80° Celsius." <- It dries out faster otherwise.

Also, check if the cooler is actually firmly secured to the cpu or not. If it wobbles, or there is some give, then the cooler isn't making proper contact.
You might even need to add washers to the backplate - MIGHT. For now, if it turns out to be loose, try remounting the pump head.
What is your ambient temperature?
At idle, you should see perhaps 10-15c. over ambient.
Since your coolant temperature is 32c. I suspect some sort of pump issue.
Perhaps there is some sort of obstruction in the pump inhibiting flow.
Is there a measure of the rpm of the pump?
If the pump is not running full out, there could be your problem.

Look into the ICUE software.
It might be mistakenly lowering the performance.
I bought this brand new AIO like 6months
Any component can have issues.
You might contact Corsair support.
Looking at the reviews for your unit, I see some 100 one egg reviews(10%)
You might review them looking for issues such as yours.
Do not be too alarmed, those with issues will post negative reviews more frequently than those with no issues.
Many such issues are self inflicted.
Me, I would have picked a noctua NH-D15s with few issues at half the price:
Jan 16, 2021
With Ryzens non centered chiplet design some coolers work better than others. Gaming temps at 90 would be concerning.

Any chance you're overclocked or have PBO enabled?