I am having a (I think) stability problem that is different from what I have seen in the past.

It has happened at OCs of 4.0, 4.2, and 4.4 ghz with my E8500. At all three OCs I have tested OCCT and Everest stable but my machine will then, at some point, shut down and reboot at random times. It happens under load and idle.

Is this an artifact of high FSB settings? I never had this happen with my Q6700 at FSB of 360 and 380 whereas I am now using FSB of 424-464. Or is this a hardware issue? I have used three different motherboards with similar results (P5K deluxe, P5Q premium, and now Maximus II Formula. Other components as listed in sig.

Enlightenment please.