I had the same problem for a long time with my XFX 4850 512mb and even though I could make it happen slightly less often with some tricks It would still happen. I eventually had to use rivatuner to underclock it down to 550mhz but with more recent drivers I can set it to 600mhz. I have actually sent the card into XFX who found it faulty and sent a new replacement which had the same problem just not quite as bad!
Things that I have found that lessen the problem.
Go into your bios and set the PCIE clock to 100mhz not auto.
Run the games on different settings, if the frame rate is low (yes low!) enough or high enough it won't crash.
Things that I have eliminated in the past.
Heat: I have an accelero s1 rev 2 with 2 120mm fans on it plus the front case fan moving some air towards it as well as zalman copper vram heatsinks and it never passes 40c on gpu and 50c on gpu memory IO.
Power sorta: I have ran the power supply test in occt several times with no crash.
Strain: I have ran furmark, futuremark 03, 06 and vantage, OCCT, heaven benchmark dx10, and the ati tool artifact scanner with no crashes but in certain games such as crysis I still get crashes unless I underclock a lot.
XFX brand: Had an xfx 8600GT that actually overclocked better than some voltmoded 8600GTs and even if it had a display driver crash it would just restart the display driver and in the worst case senario cause the game to crash but I guess that does not rule XFX out with ATI cards, maybe they have some flaw with their 4850 board design, though I have heard of this happening with an MSI card.
DX10: I can run CoH, Assassins creed, DoW 2, and I will try battleforge tonight and see if it crashes.
CPU: I replaced my 5600+x2 with a 720x3 so it’s not just the AMD 5000 series CPUs
Drivers: tried all driver updates and driver sweeper, and I got the 4850 back when 9.3 was new, so it’s not just the latest drivers.
Things eliminated because of your specs.
Motherboard: Not only is mine a different brand and generation, it uses the nForce 570 sli chipset instead of an AMD chipset!
PCI-E 1.0: Your motherboard appears to have 2.0 so it cannot be 1.0.
Maybe VRAM: Mine only has 512mb so I would think it might not be corruption if but I'm not sure.
I would think it would be unlikely that any of this is causing it but do you use any of this software or have any of this hardware, it’s all I can think of that has not changed that might be able to do something.
Networking card: trendnet teg-pcitxr
Sound card: Sound blaster audigy SE
Ram: Do you happen to use Wintec AMPX memory?
Avast!: I doubt that this could be the cause, but I'm not sure.
Spybot Search and Destroy: I doubt that this could be the cause, but I'm not sure.
Ad-Aware: I doubt that this could be the cause, but I'm not sure.
Ccleaner: I doubt that this could be the cause, but I'm not sure.
Riva Tuner
ATI tool
A DVD burner that uses an old PATA cable instead of SATA
Random Info
I will sometimes get a black screen without any green lines instead of the normally line covered one.
I have successfully overclocked memory while underclocking the core without a crash.
I have tried connecting another power connector to the motherboard that the manual said is only necessary for SLI but it made no difference.
I have tried reapplying thermal compound multiple times and I use arctic silver 5.
I get no artifacts unless I push the clock speeds past 750mhz/2400mhz
I can’t think of anything else to say that might help or could be the cause, maybe someone will spot something in this info.
Ignore my awful spelling and grammar, or I shall crush you!
