Cooling low-profile CPU cooler for an i9-9900 microATX build

[runcyclexcski]

Hi all,

I am thrilled to have discovered this forum. I did a search for a i9-9900 here, and haven't found much, so I apologise if this has been discussed already. I have so far attempted only one SFF build (now I know the proper term), using a DIY scaffold of Aluminum T-profiles as a 'case' (500x300x100 mm outer dimensions), as most standard SFF cases seemed too boxy. I based my box around a i7-6800K, an Akasa Nero LX, a micro-ATX (ASUS X99-M WS/SE), SIlverStone SST-SX500-LG PSU, and a GTX1050 GPU. I just arranged the components to make as flat as I could, and the box has been working well for a year so far (Inventor, movie rendering, I am not a gamer though).

Well my laptop just died, and I would like to try a i9-9900K mATX build, and this time to make it more portable and more organised. I think I can shrink it to 400x250x80 mm, i.e. to take on carry-on, and use it as a chunky 'laptop' (no battery ). The only sticky point is the low-profile cooler. Are there any that are known to work with the i9-9900K (no overclocking)? I've been looking at 120 CFM+, and those were all monstrous, whereas I am after something thin, flat, and wide. What also confuses me is that the i9 is rated at 95W, whereas my current i7 is rated at 140W. The i7 has been doing just fine with the Nero LX, and yet I was advised against this cooler with the i9. Perhaps I haven't been loading the i7 that much, and thus haven't noticed any issues? May be I can just swap the stock 140mm fan on the Nero with a much larger one, and focus the air better with an adapter funnel of some sort (3D print)? Any comments would be much appreciated!

 

[tinyitx]

Intel TDP applies when the CPU works at its base frequency. When the CPU boosts up to its turbo frequency, wattage will be higher. Of course, if the CPU is overclocked, it will get even higher.

For your i7 6800K, the 95W refers to when the CPU works at 3.4GHz. By default, the CPU can boost up to 3.6GHz, which is not much higher than the base 3.4GHz. So, the wattage increase will not be that substantial.

However, for an i9 9900K, its base clock is 3.6GHz (=95W) but its max turbo speed is 5GHz. This substantial higher turbo speed requires much higher wattage.

So, while your Nero LX can handle an i7 6800K even at its turbo speed, it is almost for sure that it cannot handle an i9 9900K at its full potential. In other words, the Nero LX will work but you will restrict the CPU to work at a lower high speed limit/power limit.

Further reading:-
https://www.anandtech.com/show/13400/intel-9th-gen-core-i9-9900k-i7-9700k-i5-9600k-review/21

So, you should try to use the most 'massive' cooler that you can fit/afford to take as much an i9 9900K can offer, in terms of performance and power. There is going to be a trade off between the size of the cooler and the performance of the CPU.
One good low-profile candidate might be Thermalright AXP-100 Full Copper, rated at 180W at its stock configuration. It has 6x6mm heat pipes and is 62mm tall, including the 14mm thickness of the slim 120 fan.

Your 'case' is an open case? Just the internal frame but no side/top/bottom panels? Like a skeleton?
Post a pic or two please.

 

[runcyclexcski]

Many thanks for the tip on the Thermalight cooler. It did not come up in my searches, because, perhaps, I was looking for a much higher CFM (but of course CFM is not the only thing that matters). I wish cooler manufacturers stated clearly what wattage they are rated at. I was about to rig a small resistive heater, pump 100-200W through it, and read the temperature, to compare heaters.

Yeah, it's just a skeleton -- similar to the logo of the forum, but flat and long, rather than a cube. Will post pictures!

 

[benii]

I build 9900k with 240 radiator and its barely enough, it works but gets really loud on prime95. I have read Noctua NH-C14S would be just enough for 9900k and thats already 115mm high. My 9900k takes around 160W alone with stock boost according to hwmonitor so I wouldnt even try those smaller coolers, that noctua is over 1000g heavy and that thermaltake is only 300g so I wouldnt even try it tbh.