X99-UD4 "hard restart" when stressing with OC

[Geicher]

Hi,
I overclocked my 5820k to 4.00 GHz with 1.2V Vcore.

After stressing the CPU in Prime95 27.9 the screen will freeze and the board turns off completely after 3-5 hours and turn back on shortly after.

After that the BIOS tells me to either Load the optimized settings or enter the BIOS and configure myself.

This issue does not happen when I run the system at stock settings, in addition to that it doesn't seem to be Vcore related because the same issue will appear when I set the Vcore to 1.25

Do you have any ideas what the issue could be?

[Maggpies]

this could just be the version of prime95 you are using. at work the newer versions see to cause lock ups or 124 BSODs on the x99 chipset. Do any of the threads in prime stop running before the lock up? try one of the older versions like 27. also try setting the cache voltage to 1.1v