Quite high temps on non OC'ed i5-6600k

[Karazzi]

Hi!
I have just upgraded my CPU fan to a Cooler Master Hyper 212 Evo, since I thought that core temps around 75-80 C while gaming, was a bit high. My idle temp i 30-35 C. All temps are read in HWMonitor.

I have not OC'ed the CPU but even after I changed the cooler I am still getting a quite hot CPU (75C) running a prime95 torture test.
Can it have something to do with the thermal compound? Can that stuff expire? I opened the tube about 2 years ago or something, but made sure the cap was securely on. Forgot what it is supposed to look like coming out of the tube. I guess it was kind of glossy.
Is this normal behaviour for the CPU or should I do something different?

 

[feelinfroggy777]

75C is warm for a stock 6600k underload, but it is not crazy high. Your idle temps don't show that the ambient temperature is not too hot either. The 6600k is a hot chip and the hyper 212 is not a great cooler. Are you running a stress test for your temps? If you are running Prime 95 then 75C is fine. If these temps are from a gaming load, then it may be a little warm and it would be a good idea to change the thermal past. Grizzly Kryonaut is considered some of the best thermal paste on the market. Quality thermal paste can lower your temperatures by a few degrees.

 

[10tacle]

Yep, high quality thermal paste helps, but it only does as good as the cooler does in dissipating heat. There are now better coolers than the Hyper EVO in the same general price range like the Cryorig H7. When it comes to cooling a CPU on air, it's a combination of things that matter: case air flow, CPU cooling, and thermal paste. If all three are combined and good, you'll have the best cooling you can.

Regarding the thermal paste, it has a long shelf life in the tube. It's when it is applied and used for its purpose when it starts to deteriorate. I re-apply mine every two years including on my GPUs which also reduced temps from the factory.