i actually have two xfx 6870 black edition and ran into some trouble lately (after messing up my driver installation and even completely redoing the system and setting up fresh drivers
)
so until 2 days ago i had them running in crossfire mode with msi afterburner set to 1050core/300memory, no voltage adjustment (+ an additional 5870 at 950/300 with stock voltage).
if i try this now, it does not work, the system freezes right after hitting the apply button in afterburner or after a couple of seconds when i start mining.
i have tried catalyst 11.5, 11.5b and 11.6. I would really love to hear ideas why it now does not work, while it did work a couple of days ago.
also tried afterburner 2.1, 2.2beta3 and beta4 (which runs fine at lower coreclocks right now).
i must also say, that with 1050/300 my system used about 50 watts less then now (1008/575)!
If anyone knows more about working voltage settings or what voltage increase helps stabilize the system...