Re: Help me find the culprit
Looks like it had something to do with the cables. It disappeared for a while after I removed some peripherals from the power strip but came back. Somebody suggested that it might be the monitor cable being parallel to a power cable (which it was since I have the new psu out of the case untill everything is fixed) and after a little rearanging everything is ok now. It definately wasn't Vsync. it was like horizontal ripples of "noise", can't describe it better.
Anyway now some games crash after a while (black screen, monitor light goes orange no signal found. I had that btw for years like tons of other people reported over the net but happened very rarely in specific games like once in 10 days and playing in win 7 solved it) and some others (starcraft 2 namely) started showing artifacts and after 10 minutes or so colours go nuts (screen goes white-ish, menus go black and minimap pink and green). Also temps under load go easily at 80 C now. So I gues I'm off looking for a new gpu.