Yeah, you should be doing much better than 25 fps with that rig - especially at 1080p. Are you sure both gpu's are working? Is crossfire supported for BF3 at launch?
If you're looking for a few suggestions to improve your frame rate without much visual quality loss, setting Ambient Occlusion from HBAO to SSAO and turning AA down/off got me big improvements. Neither of these detracted from the visuals too much and I added almost 20 fps as a result. I left everything else on Ultra.