i5-8600k Throttling at 70*C

[WigglesR]

Preface: I’m an overclocking novice

My i5 8600k is throttling to 3600 MHZ, ~1.06V (even lower sometimes) at around 70*C while running P95 and I have no idea why. I’ve even clocked it down to 4.7@1.24V (lazily lowered voltage to see if it would fix issue, I could probably get it lower @4.7) from 5.0@1.29V, and it still throttles after about 15 seconds of running P95 according to CoreTemp. The 5.0@1.29V also throttles running TimeSpy in 3dmark, but I got it to be stable at 4.7 while running Time Spy.

Build:
i5 8600k
MSI GTX 1060 6 GB
MSI Z370 PC PRO
Corsair Vengenace LPX 16 GB @ 3000
Corsair H80i (quiet preset, even at extreme CPU always throttles @ 70*C).
Corsair RM1000x PSU
250 GB 970 EVO
1 TB WD Blue
Phanteks Enthoo Pro M case

 

[7664stefan]

With around 70C the temp should not be the issue unless thermal protection - here I do not know MSI boards well enough - is somewhere set to 70C as a temperature target.
Are you experiencing the same also at 4,7Ghz where you wrote it is running stable? What if you reach the 70C at 4,7Ghz?

With which tool are you seeing the 70C please?

Looking into the related TH review a lot more capable cooling solutions end at around 70-80. I have my doubts that the H80i can achieve the same result.


https://www.tomshardware.com/reviews/intel-coffee-lake-core-i5-8600k-cpu,5264-11.html

 

[WigglesR]

I’m using CoreTemp to see temps, and experience the same result with the 4.7 OC. Whenever it hits 70, no matter what, it throttles. Though, the 4.7 takes a lot longer to hit 70.

 

[WigglesR]

I had to set the wattage limit higher. it was at 120W.

 

[7664stefan]

Yep! I was guessing something like this limiting wattage or thermals. Good that this is solved then. Same happens btw also with the temp and power target on GPUs.