This is a long shot but im just posting this solution that i found for myself. I think its a Crossfire issue. I got the game running with the Oblivion profile with RadeonPro, but sometimes when i exit a house or open/close my map, the game would drop to single digit FPS and stay there, and my fans would go down, meaning my second card is probablly not being used anymore. Like i could force Crossfire using RadeonPro profile, but it was inconsistent and would shut off during the game.

Solution is simple: lower AA from 8x to 4x fixed it perfectly for me. Now we just have to wait for the new CAP so we can truly max out the game with crazy frames.