Looking for Cooling ideas for Intel i9-9900K, i7-9700K, or i7-8700K


Jan 3, 2017
Hi All,

I have recently suffered a motherboard failure, and hence I’m using this opportunity to upgrade my Motherboard, CPU & RAM.

I haven’t decided upon whether I want to go for an Intel i9-9900K, i7-9700K, or i7-8700K but I am looking to perhaps do a slight overclock on one of these CPUs.

I’m looking at the ASUS TUF Z390 PRO GAMING Motherboard, with 16GB of Vulcan TUF DDR4 memory. This will be put into my existing mid-tower Coolermaster N400.

Which brings me on to the question of cooling, I’m looking to go for an air-cooling setup. I’ve measured the case and I’m estimating around 160mm of clearance for a CPU cooler - the Coolermaster website states the clearance is 164mm.

The RAM height is listed as 32mm, so I don't think I'll have a problem here.

My initial thoughts were the Noctua NH-D15/Noctua NH-D15S but they have a height of 165mm, while the DARK ROCK PRO 4 comes it at around 162mm, both of which would be either slightly too large or tight to the case.

I was wondering if something along the lines of the DARK ROCK TF would provide sufficient cooling for one of the above CPUs?

I’m also happy take some recommendations or ideas that I can research further!
The 8700K is quite snappy as it is for gaming, but, the 9700K does seem to surpass it slightly....

The 9700K and 9900K both run quite darn warm it seems, requiring disabling the MB/BIOS power limit of 95W TDP to exceed about 4.2 GHz on all core turbos, and, even attempting running all core MCE-enabled at stock max turbo will require VERY healthy coolers, ~150-160 watt TDP, and, at about 85C temps, and that was with an excellent 3 fan radiator/pump affair or NH-D15. (With 95 watt limit in place, reviews seems to suggest the BIOS will limit all-core operation to about 4.2 GHz on all cores, which, although quick, it would seem the 8700K running all cores at 4.7 GHz would *likely* be faster anyway...)

Folks hoping for easy all core /MCE operation at 5 GHz w/ 9700K/9900K at below 95-99C are likely to be disappointed, I fear...


The DARK ROCK TF is supposed to be rated for a TDP of (up to) 220W.

The 9900K is a 95W TDP part. With some overclocking, you're going to be increasing that some - but Rock TF should still be sufficient.

Noctua NH-D14 or D15S should be sufficient too - and fit. The D15S is 160mm in height, so should fit. The D15 has a front fan you'd have to raise to clear any sizeable DIMMs, raising the overall height - the D15S is a single fan design, with improved RAM clearance - so would be 160mm when all said & done.
The Coolermaster specs say you have 164mm available for an air cooler.

The noctua NH-D15s needs 160mm so you are good there.(the older NH-D15 needs 165mm)
Here are the noctua TDP guidelines and specs:

While the NH-D14 will fit from a height point of view, I used one once and it impacted by graphics card mounted in the first pcie x16 slot.
The s variants of noctua are redesigned for better compatibility.
They are offset a bit to clear graphics cards and are also designed to clear tall ram heat spreaders.

I have seen a test where the NH-D15s slightly beat the DRP4 in cooling performance.
Don't know about DRP4 clearance issues.
My D15's 2nd fan once adjusted upward for RAM would bump my Corsair 100R's windowed case, so i merely moved the 2nd fan a few inches away, and utilized it as input case fan, blowing air directly onto the tower stack only a few inches away anyway. Temps still quite good, and whisper quiet.
The NH-D15 and variants are EXCELLENT coolers, bascially the performance of an H100i with less noise and no risk of leakage. NH-D14 isn't as good and it's not because of the heatsink, but because it doesn't come with PWM fans, which means unless your motherboard has voltage regulation for fans, they will run at a fixed speed which is super annoying. If you do in fact only have 160mm to work with, I would personally go with the D15s, but you can always just get an AIO since there for sure won't be any compatibility issues. You can't really make a bad decision, but generally high quality air coolers are a better investment because they are basically indestructible and offer similar or better performance for the money.
Also, just curious, but since you're already spending that much money, have you considered getting a better case? You could get a MUCH nicer one for ~$100 with tempered glass and be able to see all your new toys, plus no compatibility issues.


Jan 3, 2017
I would like to thank everyone for their inputs, it really is appreciated!

So after some consideration, I think the NH-D15s is the one I should go for.

I hadn't even thought of this, and this would work if I do not have the clearance for the 2nd fan, although I think I will have clearance.

I don't want to purchase a new case just yet... only because I would like to make some other changes as well, such changing some hard drives, and then it becomes too expensive - I take you point though! When I purchased this case, many years ago now, I didn't take much thought about the case, and in the future, it's something I think about it a bit more.
Oct 5, 2018
I used liquid metal on NH-D15 plate, and heat sync for I9 9900K, it boots at 5.0GHz and 4000MHz memory, and runs up to 5.4GHz with INTEL XTU. High humidity, like a rainy day, I load optimized defaults that goes to 5.02GHz in a very efficient way. Likely, only benchmarks, need extreme cooling, I have three fans, Cosair mid tower, I may double it. I have to look at how fans are positioned for air cooling the CPU, inward, or outward.
During the BIOS changes, the system heats up, it almost stops the fans unless you run DC, and full speed for all fans. Which I do, when you load optimized defaults it resets the full speed setting.

I'm thinking, six fans, they are very quiet, no big deal. Have to try it once anyway.

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