6700k OC w/ MSI z170i No longer steady

A wierd question that I'm hoping someone has the answer to;

I got back from work and my PC had dropped its BIOS config. Its happened once or twice before and not sure why but usually its just a matter of re-applying my settings and back to normal.

A while back I got a stable 4.7GHz OC w/ 1.355v and temps around 70c under aida64 stress test.HWINFO showed steady core clock and voltages only slightly over what I had set but they were also steady.

After setting my OC again this time cores would drop down as far as 3.6GHz under stress test no matter what settings I used in BIOS. Even tried stupid voltage of 1.5 with a 4.6GHz and still no steady clock.   

I have set everything to fixed or override in BIOS:All core multiplier: 46Multiplier type: fixedRing: 4100CPU voltage mode: OverrideCPU voltage: 1.355 (had stable 4.7GHz for over a year with this voltage)Digitall Power: Both on mode1 (this seems to be only equivalent to LLC and mode 1 lets CPU have more power)

I cannot find any other settings like other motherboards I have had which sets a max voltage

Anyone have any ideas or given this sudden change has something in my motherboard just died?word counterVidMateMobdro

Edited by masharustova - 15 Aug 2019 at 12:08pm