The bottom line is when CrossFire works it works well, but a lot of its performance is out of the hands of ATI and in the hands of the game developers who can choose to support this feature and make it work properly or plainly do not support killing its true potential. Hopefully ATI will make driver patches to help performance in games that do not support CrossFire out of the box. At this moment any two ATI cards you buy no matter who is rebranding them will work together in Crossfire mode.
http://www.youtube.com/watch?v=FYfzKdU3WKw
