I have a 5870 and a 6990 together under Windows 7 32 bit. The 5870 is the primary board attached to the monitor with the 6990 dummy plugged. (This isn't a dedicated miner so I wanted the 5870 to take the performance hit whenever other programs needed the graphics card.)
Whenever I try to install drivers (Catalyst 11.6) they install without any problems but I noticed that in Afterburner no driver information is displayed for the 6990 GPUs while when I shift the settings to the 5870 the driver version shows up correctly.
Does that mean the drivers aren't "reaching" the 6990 when they install?
I'm asking because I'm only getting around 350mh/s per GPU on the 6990 and have been trying to get them up to the 432mh/s or higher (as discussed here: http://forum.bitcoin.org/index.php?topic=25798.0;topicseen
) without any luck. I've tried using Phoenix 1.50 with all the recommended flags and still the hash rate won't go up.
So I'm thinking its the drivers?
Any help is appreciated!