Running dual non-reference 6950's at 910MHz Core, 650MHz Mem, 1149mV, 79 degrees each under 98% load.
Windows 7 64-bit, running the Catalyist 11.1 drivers (11.2+ drivers cause screen tearing when I attempt to boot into windows).
GUIMiner client, 2 OpenCL workers pointed towards BTC guild.
Flags for both workers, -f128.
My buddy is currently running a Win7 x64 box with a pair of non-ref Diamond 6950s (flashing the bios and still seeing 1408 shaders was a sad, sad day) co-lo in my living room
![Tongue](https://bitcointalk.org/Smileys/default/tongue.gif)
Sorry for the late reply. No other flags, just running fine with -f60 now. Screen tearing was to the point that it was impossible to navigate through windows. I'm honestly not sure if 'tearing' is the right term, but a bunch of horizontal multi-colored lines with an overall gray hue went through my screen covering the entirety of the windows desktop - it was impossible to do anything, and I'm not even certain an autoloading miner would even get started. I think 630 MHs is respectable all things considered if you don't want to burn out your fans/cards.