i have recently bought two Gigabyte HD7850 OC for crossfire replacing my GTX560 SLI. Everything were running fine on NVIDIA so i have replaced graphics, reinstalled Windows and now i cant play any game longer than 15 minutes, PC completely freezes... mostly blackscreen or monitor shut down, all i can do is hard reset. I have fresh Windows, newest drivers, all components are fine and now when i changed my graphics everything is screwed up. Its not doing while IDLE, or watching movie/internet... its just games freezing my PC. I have tried all crossfire settings in Catalyst and none of them helped, one single card seems to run stable so its crossfire. I think Catalyst isnt really ready for crossfire yet, but im sure im not only one having 2 new Radeons and so far i havent find anyone complaining about PC freezing. Also i have read a lot of crossfire reviews with new Radeons and none of them tells anything about complete PC shut downs during tests, maybe some lesser problems but not this insanity i am experiencing. That makes me wonder if one of my graphics is bricked or something else. I really dont know what to do to fix this.
I was pretty happy about performance increase over GTX560 SLI... around 25 FPS increase in most games making decent running games (Battlefield 3, Crysis 2 and such) run perfectly as i wanted... the performance is exactly where i need it, watt eating is almost at half compared to GTX560, IDLE 3W technology is awesome.... but... this freezing just freaks me out and im hopeless. I was using GTX460 SLI, GTX560 SLI without problems or stuttering in games most ppl encountering and was pretty happy about 2 graphics setup, never had a single problem with it. Now with new cards this problem appears and i have very bad feelings.
Some important info:
I have CPU on default clock with turbo boost which is 3.8Ghz, memory freq set to auto which is 1300Mhz, newest ASUS bios for my MB, temeratures are fine on all components, PSU is more than enough...750W for new less eating graphics. I have tried both crossfire cables just to be sure, i know if it was cable crossfire couldnt work, but you never know.
Its happening in every game, as i said i have made my own clock profile with 4.5Ghz tubo boost on processor and 1600Mhz on memory. Even with that used in any game i can play around 15 minutes then PC freeze. Im starting to think that gprahic cores are just bricked and will go for warranty. I was bothering with this all day and i havent find any solution. I ended up installing 3DMark 2011 and when i tried to run it i did get bluescreen, after that even GPU-Z engaged bluescreen.
EFI bios is setting memory freq automaticaly based on your CPU, IF you dont choose your own freq and thats what i did, there are options 1000Mhz - 2200 Mhz and you can pick w/e you want or you can pick Auto and your memory will be clocked by bios.
Its in my profile, but ok Kingston Hyper-X DDR3 1600Mhz CL9... the problem is not in the memory anyway, and the default BIOS clock for these is 1333Mhz i misstyped it. Anyway i was bothering with this whole weekend and ended up with same problem.
Single graphic works, both of them, in all games... connected as crossfire freezing PC, i have tried every single component on stock clock and it didnt help (belive it or not but default clock for 1600mhz memory is 1333). So graphics are both or one of them bricked or my PSU magicaly burned during graphic card switching and cant provide enough power (i dont belive it anyway) or something is wrong with my motherboard that could magicaly break too during simple GPU switching.
I think the best solution to this is get my case and give to warranty employee. If i give them just cards and they say they are fine its not gonna change anything and i end up with PC that have something screwed up inside.
I guess it's not just your problem, I have it too, with two HD7770s in crossfire. Disable the crossfire, and everything is well with either card. The most stable driver that works is Catalyst 12.3, other than that there is Catalyst 12.6 which came out Thursday last week and 12.7 Beta...don't use those either, they do the same thing. Catalyst 12.4 might work, but 12.3 will work for sure. Anything below driver 12.3 will not support your HD7000 series cards, so don't even try those. Or you can disable crossfire until AMD decides to fix this.