Does cooler performance really matter for non-delidded CPUs?

[yoadknux]

Hi guys,

One conclusion that I reached from overclocking my 8700k with 3 different coolers is that, for non-delidded chips, once you pass a (not very high) cooling threshold, your temps won't get better. I tried three different coolers: Corsair H75 (120mm push-pull), Corsair H105 (240mm pull), and Arctic Freezer II (280mm push). I also tried various fans, like stock Corsair fans, Be Quiet! Silent Wings 3, Noctua NF-A14, Arctic P14... Temps got to 90c (under P95 and other stress tests) regardless of pump, radiator and cooling.

What I told myself is that the difference between the three coolers is the heat capacity, but they all extract the heat in the same manner, by being attached to the CPU's IHS. But the IHS doesn't extract the heat well to begin with (unless delidded) which means, heat capacity of the cooler doesn't matter - well, provided you have anything that is above average.

This makes me wonder, I see so many builds with 240mm/280mm/360mm radiators. Considering that most users don't overclock, and among those who do overclock, most do not delid - Are people (me included) just throwing money at big coolers that don't really do anything? Or perhaps I have missed something in my testing? Maybe the heat load is extracted and just overwhelms all the coolers I tried?

By the way, this is very different from what I experienced when I water cooled my 1080ti, in which even going from 120mm to 140mm made a noticeable (10-15c) difference.

Would love to hear your opinions!

 

[Mr.Scott]

You're a little misguided. The bigger coolers DO work better, but..............when you're starting with a bad tim application under the IHS, nothing will help that except a de-lid and re-tim job. Bigger cooler can't move more heat if the heat ain't gettin to the cooler.

 

[EarthDog]

You're spot on...for the most part.

The problem today with modern intel chips is the small die. It just can't get enough heat out. The 8700k used the crappy thermal paste so it was know for this. Even the new chips with solder have this problem. That is why you dont see a huge difference between the coolers.

 

[trents]

To put it another way, the extra heat removing ability of large coolers is largely wasted because the cooling bottleneck quickly becomes the surface area interface between the die and the lid rather than the cooling capacity of the cooler. When that point is reached, the cooling efficiency of larger coolers rapidly succumbs to the law of diminishing returns.