I have a hackintosh running on a Gigabyte P55M UD2. It has run without a single issue as a hackintosh for about 9 months, and the machine is about 2.75 years old. Never had issues when it was just linux box. Power supply is 750 Watts.

It recently started spontaneously rebooting, no seeming connected to any particular use case or ram/cpu load. There is no hanging or anything, just suddenly acts like the power went out. The frequency of which seems to be increasing. I've tried using just one of each of the two ram sticks, and it happens with either one in. I'm not sure what to try next, is there some way of determinging whether it's a mobo, cpu, or powersupply issue short of replacing them all?

thanks! Iain