I should also add that my PC once shutdown - when playing the Space Marine demo, in fact - and a quick look showed the CPU fan to be SOLID fluff.

Cleaning it out, the running temp of the PC dropped over 10 degrees :)

Oddly, my old 5670 was always dust-free (big spacious fan) but this 650 TI Boost has a faffy cooler which will need defluffing a fair bit I reckon.

Time for a new case too - with the modular cables it now looks like an explosion in a parts cupboard...