Hello, I've recently purchased a new build and finished setting everything up a few days ago. The build is: phenom ii x4 955be 4gb ocz platinum RAM samsung 1tb spinpoint f3 hdd msi radeon r5850 twin frozr vga 1gb foxconn 790gx motherboard ben q 21.5inch hd screen cic 750watt psu Now, I've never had trouble assisting my friends before in setting up their builds, but it seems fate has struck me when I've attempted my very own first build. After installing windows 7 ultimate 64-bit on the system and updating all drivers, I decided to test my new system with a few games. Crysis, just cause 2 and civ v. After playing just cause 2 for an hour or 2 with all working fine I exited the game and tried crysis, but after having played crysis for approximately 5 mins, strange artefacts began appearing all over the screen, little square white boxes is how id best describe them. So I exited crysis and tried civ v and sure enough after about 10mins of gameplay the little artefacts began appearing until spreading across the entire screen. I then decided to re-try just cause 2 and play for a little longer, but there was no need as after a few mins the artefacts appeared yet again. They now appear in every game I've installed but only after several mins of perfectly smooth and playable gameplay. I've reinstalled all drivers several times, updated windows, overclocked and underclocked the 5850 and to no avail. Luckily my motherboard has onboard graphics as the last time I turned windows on with the 5850 installed I got a blank white/greyish screen and nothing responded. Indeed until now I've been unable to load windows with the 5850 installed, and I can only guess but it actually seemed like the problem was getting progressively worse up until then. Could anyone possibly assist me with this annoying problem? One possible thing I have noticed but am not sure if it could make a difference is that my psu comes with only one 6-pin connector, and the r5850 requires 2 6pin connectors, so I've used the one 6pin that came with the psu and used a 6pin to molex that came with the card to connect both to the psu. I'm sure there is ample wattage though and it seems strange that the card works fine until minutes into all of these games... Any help would be greatly appreciated. Thanks in advance. James I dont know how to upload images to here, so i found an image that looks exactly like mine containing identical artefacts, (i even downloaded unigine to test this and got same artefacts therein).