1) GPU = graphics processing unit. Insofar as heat damage is concerned, it's the capacitors that are more often the fail point. Worth noting is the fact that electronic parts usually fail in response to sudden temperature change. (A light bulb burns out when you switch it on, seldom while it's in use. 2) depends, a) have you altered the default setting of [idle] in the config to some other value? b) do you have a multicore processor? The standard windows client will use only one core.