I recently bought a new sapphire 5850 and put it in my gaming pc. I have had so many issues its crazy!! I have had green & grey stripey screens of death. Sometimes, it will pop up at the start of games very briefly and then not happen again for like hours or not happen at all that session. Some games had the problem (split second) while it seemed i could play others easily (GTA 4 & episodes). I have tried updating my bios and changing the drivers to 10.3, 10.1 with flickering screen hotfix. Oh yeah, and something is weird too. I may have a whole day with no problems apart from the occasional minor grey.green screen which goes away quickly. Then near the end of the day the pc goes crazy and will just black screen and reboot itself and then every time it loads up it flickers like crazy, even on w7 loading screen and finds it really hard to load up, when the flickering gets bad it just black screens and reboots again. If i leave it a while then it seems ok or overnight, the next morning it boots ok. I heard that some people were saying the idle voltage is too low, i tried afterburner to overclock the voltage a tiny bit and i thought that helped cos yesterday i had a few hours of gaming with no issues. Then had the blck screen and rebooting problem in the evening. Tried to take out and re-seat the card (the second time i have done this) and then the system ran fine again. Also, i notice afterburner makes my card become more active, you can hear the fans more etc. i am wondering if a mild overclock might actually help it run better. I will also run a memtest tonight. Any help would be awesome.
Cant give detailed specs cos i am on the ferry to work I have a gigabyte ga-- something motherboard, 8gigs of ram & windows 7 ultimate. I am also running a 650w coolermaster psu and samsung syncmaster 22 display. When installing the card i used the 2 6 pin connectors that were in my dual 4850 crossfire setup rather than the one supplied in the box of the 5850, as i couldnt find a way to connect it to the psu!!
Have not herd of this issue on more recent 5800 series cards but when the 5850 1st came along quite a lot of people reported the same issue that you have.
Turned out to be faulty cards.
The connectors you used form a dual 4850 setup should have worked fine as long as they were the standard 6pin VGA connector and the output of your PSU is plenty to run the card (had mine on a 500w enermax un till recently).
Would advise digging out your receipt and contacting your vendor for a new card.