I recently started having strange graphic issues when gaming. Since building this rig about 4 months ago I've had no issues at all but about 4 days ago I started having major issues while playing World of Warcraft. Was getting major artifacting with lines running all over and certain surfaces blinking. Though it might be the game as the problem seemed only to be in WoW, so I messed with various settings and nothing helped. Then I tried updating my graphics driver and that worked for about a day. Then it started back up again but now in addition it would occasionally freeze, go to a full screen of a random color, then black, then return for normal for a bit. Once it dropped to desktop and windows notified me that my graphics card had failed (I forget the exact wording) but had recovered, then popped back to normal. This pausing issue now keeps getting worse getting up to maybe a few seconds between pauses and the artifacts are getting worse as well making the game unplayable. Also now the issue extends to other games like Mass Effect 2 where certain surfaces blink or seem to be covered with static. Outside of games however there are no problems. On the desktop and when web browsing all is totally fine. Tried re-updating the graphics driver (to newest 10.8) in case I messed something up the first try, but with no improvements.
Just tried stress testing it to see what the temp maxes out at when stressed. Used FurMark and ran that for a while and it plateaued at 69C and maxed at 70C. Also saw none of the problems I've seen in games during the test.
run hot cpu tester pro for 6 hours to test your hardware then yull no if any hardware is bad. make sure you have a good power supply. Then after all that try differnt chipset drivers and video card drivers. good luck.