you can read about thermal problem all over the place. I think there is an issue between Die and Heatspreader.
What else can cause that:
prime95 small FFT.. CPU temperature jumps instantly to 95°C and even after minutes the groundplate and heatpipes of my DarkRock pro 4 is not much warmer than my hand, where as the vrm heatsinks are twice the temperature i would guess. I reapplyed the cooler (with noctua nh1) as well as the stock cooler 5 times in total, with similar result. I realy dont want to delid my CPU, but i dont know what else can couse that behaviour other that bad contact to the heatspreader.
If the cooler would be hot as well this would be a total different thing, but it is not hot.
2x16gb cruical balistics
bequiet dark rock pro4