Overclocking Troubleshooting Help 8700k

[lordmatthias]

Long time creeper, first time poster :), any help would be greatly appreciated!

So I have a bit of a weird issue, I noticed my CPU was getting hotter than normal running some games (85C in BFV), so I cleaned out my case and also re-applied new thermal grizzly paste (it had been 2 years and the original paste I used was already pretty old to begin with).

Tested again and was happy with the temps under load running prime 95 (seeing a spread between 60-66C). My VID is running 1.38-1.4 and power pull is roughly 126-133 watts).

I let it run for about 15 minutes to make sure its stable etc... all of a sudden I notice my temps skyrocket to 88-93c and my VID is running 1.35ish and power pull is 174 watts!

I checked my OC settings against a couple guides and everything looks correct in the bios, at this point I am sort of at a loss for what is causing this. I am thinking this is what is causing the the issue I am seeing in some games. At this point I am at a loss for what is causing the instability. It seems to happen in Prime 95 roughly 10 minutes after kicking it off. I could use some advice on what people think it could be.

Specs

CPU: i7 8700k, 5ghz OC all cores @1.330VC
Cooler: Corsair H115i
Motherboard: Gigabyte Z370 Aorus Gaming 5
Power Supply: EVGA SuperNOVA 850G+ 80 Plus Gold

Screenshots attached

Normal State Under Load (Prime95)
https://www.dropbox.com/s/m1brdm9gor...0CPUZ.PNG?dl=0

Issues Presenting Under Load (Prime95)
https://www.dropbox.com/s/5ctgfom9qf...0CPUZ.PNG?dl=0

This is the main guide I reviewed to validate my settings: https://www.youtube.com/watch?v=mcZkEZ8x3oA

Any help is appreciated, I don't remember it doing this when I originally built the machine at the end of 2017, I did a 48 hour burn test with no major temp spikes, and this is bumming me out 

I have tried increasing the cpu voltage to 1.38. I am also wondering if the newer version of prime 95 is introducing a new instruction set, as it seems to happen pretty consistently around the 10 minute mark.

[Mick Naughty]

Prime should have temp variances as it has load variances. Unless you turned all that off.