Gtx 670 problem

ArtiMan

Honorable
Oct 25, 2012
11
0
10,510
Ok so i built my pc 4 months ago and i slightly overclocked my 670. I was able to play battlefield 3 and bioshock infinite on ultra but now that im trying to play metro 2033 and skyrim my computer crashes. Is it my videocard? And also sometimes i see vertical transparent lines on my screen while playing, do they have to do with AA? Also my clocks are under the average. Boost-1085 MHz. Pleas help and here are my specs
i5 3570 k
8 GB RAM
620 Watts