Hello! First of all, to be clear - I don't do any OC. Putting my boxes together by myself gives me enough thrills and fun. I prefer to tweak my software . I bought Sapphire HD7950 DualX Boost (925/1250 stock clocks) half a year ago. All of the games ran fine. The only one that had problems was Crysis 3 (that was one of the games I tried first). It randomly crashed with grayish vertical stripes. Only hard reboot helped. I thought it was driver issues at the time and forgot about it, because I didn't like Crysis anyway. The problems reappeared when I wanted to play Metro LL. It crashes randomly too. Sometimes it's the stripes, sometimes gray screen, sometimes black screen. Only hard reboot works. There are no artifacts, game runs close to 60fps most of the time. Batman Arkham Origins has the same problems. The thing is I finished many other demanding games on this card (like FarCry 3) with no problems. First guess - heat. Nope, that's not it - card stays cool at 60-63°C during gaming. CPU stays at 60-70°C during max stress too. Second guess - PSU. Not that too. I bought a brand new Lepa G750-MAS - didn't help at all. Third guess - RAM. Left memtest running for the night - 100% OK. Switched the sticks around - didn't help. Disabled dual channel - no dice. I tried updating mobo bios, updating/downgrading drivers, reinstalling system, even tried Windows 8. I logged temperatures/voltages/clocks/fans from all of the sensors and there are no anomalies before the crash. Everything's solid and stable at all times. I noticed some other strange things too: - I can throw Furmark, OCCT, whatever at it and it doesn't crash, everything's stable. Well, temps during stress tests are around 70°C (around 10°C more than during gaming) but that's perfectly normal. - During burn-in in Furmark the core clock is being throttled back to 850 most of the time and the vcore constantly changes oscillating around 1.0V. During gaming vcore is stable at 1.17V. That's probably PowerTune in action, but I thought that it isn't supposed to change vcore, only the clocks. - The card has two bioses 015.029.000.002.000000 (no light) and 015.030.000.001.000000 (blue light on the bios switch). The strange thing is both bioses have the same clocks (925/1250) but the second one which should be faster has even lower PowerTune limit. The card won't accept any other bios - compatible (dev/subsystem id) or not. I tried all of the 100% compatible ones and a few others. Computer won't boot, no POST, just black screen. There absolutely no problems with my old GPU (GTX260), so I doubt that some other piece of hardware is at fault. Trying to RMA is a last resort because Sapphire doesn't allow direct RMA and I lost the receipt. I can try and reason with the guys from the small shop, where I've bought it (I ordered it on-line but picked it up in person, so they have a record of the sale) but I have to be sure it's the card. My box: FX-8350 Asrock 970 Pro3 1xHD7950 Lepa G750-MAS 2x4GB RAM (plain kingston sticks, not some extreme OC stuff and whatnot) 1x spinning HDD If anybody's wondering - the PSU has single 62A (744W) 12V rail and according to some in-depth reviews it's quite good. 750W is more than enough to handle my system.