CPU Runs too Hot

[Telepath]

MB: Asus ROG STRIX Z370-E

CPU: I7 - 8700k 

GPU: Nvidia GTX 1080

Boot Drive: Samsung 970 EVO 500GB

PSU: EVGA SuperNova 650 G3

Cooler: NZXT Kraken X62 280mm

 

I feel that my CPU is running way too hot but I'm not sure.

I ran some tests and these are the numbers I've got.

Average Temp While Idle: 42 Degrees C

Temps Under Max Load: 86 Degrees C

 

It's run at these temperatures since the computer was built, and I have removed the CPU Cooler before and re-installed it to make sure I didn't do a poor thermal paste job.

 

Is this normal? The CPU is not OC'd. Though it does always run at Boost Clock (4.5-4.7GHz) even when Idle. I'm not sure why, I would expect it to clock down when not under load.

 

Feel free to ELI5, I'm far from an expert with any of this.

[Husky]

I don't have experience with that cooler but I do know that Intel chips run extremely hot nowadays and those temps sound quite normal to me. My 6700K (when I had it overclocked higher than I have it now) ran at around 90C and I have a Corsair H110i GTX.

 

As long as the temperature does not exceed around 90C then you should be good. Intel CPUs are designed to operate up to 100C, where they will start to thermal throttle. If they go past 100C then the system will shut down.

 

As for the high clock speed during idle, check that your Windows power plan settings are either on Balanced or that you have gone into advanced and set the Min speed to 10% or 5% or something instead of 100%. Also check your motherboard UEFI settings as some ASUS boards have a feature called ASUS MultiCore Enhancement which messes with the turbo boost function and can cause clocks to stick at max speed. Normally this helps performance but if you are energy conscious then you might want to disable it to allow your CPU to reduce its clock speed when idle to save power.