The powersupply might not be able to deliver stable voltages. It’s never a good idea to be ‘on the edge’ anyway, you don’t want your powersupply to run at full power all the time.
Unstable OC? I cant overclock my gpu at all (radeon 4890). If i do OC it, it crashes within seconds of starting a game.
Try putting your cpu back to its default clock speed and voltages.
Also try running furmark and see if it crashes. If it doesnt, try running a cpu benchmarking app like everest.
Also tell us your temps for everything under full load would be nice.
okey guys I’ll see what I can do