Liquid versus Air cooling on the Core i9 10900K

LCS versus Air cooling

We received a question in our forums if it is possible to test both air and LCS cooling with the Core i9 10900K. So it shall be done. We received the question in a later stage and we had another motherboard installed, the Z490 Taichi from ASRock. For reasons of transparency I mention this as the thermals behave slightly differently from the Maximum XII Extreme used throughout this review. Next to that, instead of wPRIME testing, we'll be using the AIDA system stability test, the stress FPU option which is extremely fierce on the processor.

The LCS used is an old unit from 240mm Corsair. The Air cooler (heatpipe) is a be quiet! Dark Rock 4, it's a really good premium segment heatpipe cooler with on fan though, this cooler is capable of 200 Watts, which should be sufficient with a 125W TDP processor right? Let's fire up AIDA, and again, the FPU torture test is totally extreme for testing. 

So LCS has a bit more capacity overall, which is what the 10900K needs. Under full stress (AIDA) we peak to roughly 78 Degrees C. Remember, this processor defaults. This value is high but remains acceptable. Now let's move to the heatpipe cooler. 

During the AIDA FPU Stress test we reached ~95 Degrees C on the package sensor. Ergo, we cannot advise your average Heatpipe cooler on the 10900K. What's the reason behind all this? Well, have a peek at the next screenshot. 

So here's the thing, peak TDP matters, while Intel is listing the processor at 125 Watts, the reality is that is has a PL2 state that allows it to double up that TDP value for roughly 1 minute (or a timeframe defined by the motherboard BIOS). Most Heatpipe coolers reach a cooling capacity of 150 maybe 200 Watts. The Dark Rock 4 can manage ~200 TDP, if you look at the red highlight you cans ee the processor easily passes 200 Watts, the heat accumulates and the cooler then become inapt to cool sufficiently. Perhaps with a very premium dual-fan Heatpipe cooler you can tame this beast. Other than that, go with a good LCS kit, as they simply have more cooling capacity to offer.

I'll state it one more time, the AIDA FPU Stress test is nearly unrealistic and almost viral like on the processor. So what you see here is pushing that CPU to its extreme.