I'm running two 5850 gpu's and MSI Afterburner claims that both are working when I try to mine with them, but they each only work at 50% capacity. When I kill one thread, or initially start mining with only one device specified, that one card runs at 100% capacity. It's ALMOST like it's pretending to use both cards, but it's just splitting the resources of one of them up. Again, MSI Afterburner shows 48-49% usage in both GPU1 and GPU2. I have a 890fxa-gd70 motherboard on Windows XP/32, not in crossfire mode, and both cards (two Cypress devices) are definitely visible to poclbm, phoenix, CCC and MSI Afterburner. Using phoenix versus poclbm seems to make no difference.
Has anyone else experienced this?