Question High cpu temperatures (spikes at 100% usage)

[mucuma]

Hi, I recently noticed a huge issue with my CPU cooling. Even when my CPU is idle, it shows 40-50°C temps across all cores (which is by my guess fine) but this is somewhere betwen 1 to 5% load (liquid temp is stabilized around 38°C when iddle). In case of higher usage, temperatures spikes very quickly to dangerous levels (up to 95°C, which i set as thermal throttling in BIOS). For example 30% usage is somewhere between 80°C to 90°C, in case of full usage (100%) by rendering software or even some benchmarks like cinebench r15, temperature rises to 95°C in matter of seconds (2-3 sec). What could be wrong?

Components:
Intel I7 7820x, overclocked manually to 4.3GHz (one core to 4.5GHz) (not delidded) (room temps somewhere around 23°C)
MSI XPOWER GAMING AC MB
Corsair H115i 280mm Extreme
EVGA SuperNOVA 850 G3 - 850W
G.Skill F4 3200C14 2x 16GB

What i tried:
Remounting the cooler, tightening screws, cleaning whole computer from dust.
Checked all cable management especially that related to cooler.
Updating to latest cooler software, updating the latest BIOS driver.
Disabling all things that might cause the issue in BIOS - eg overclocking, setting AVX offsets. WIthout OC, idde temperatures was a little bit lower, 37-45° but spike to 95°C was still an issue in case of 100% usage.

I currently do not have any thermal paste but i also want to try replace the old one which might or might not help.

Any idea what might cause this issue and what should i try next? Im starting to be a little bit desperate.

 

[Lutfij]

FYI, you will need to reapply the thermal paste with a quality product and see if you get better temps. Just remounting the cooler doesn't solve it and causes more issues with the paste developing pockets of air. Which OS are you on and on what version? I'd ask you to backup your critical content and proceed with reinstalling the OS after recreating it with Windows Media Creation Tools, assuming you're on Microsoft's Windows environment.