Ok so. i bought a 670 and installed then my pc started 2 randomly shutdown.. how ever i took it back out and put my old 5850 back in and shipped the 670 back to where i got it.. yet to realise.. it is still randomly restarting WHICH it didnt do before i got the 670. i have a brand new cougar cmx 1000w power supply. with an i5 2500k gigabytez77x-d3h i have no idea why it is restarting im in the middle on testing my ram but.. will memeorty just black out my pc and automatically re-boot?