DH Preview: ATI's Crossfire tested ....
 

Considering how fast paced the PC industry moves you would have thought
that a delay of over a year since SLI was introduced would have given
Nvidia such a massive market segment share that it would be unbeatable.
Unfortunately though, despite SLI being available it was far from the
perfect solution at the time of launch with issues such as lack of game
compatibility and having to use matched cards being factors that made the
purchase undesirable for many hardware enthusiasts. It has to be said
however that Nvidia have improved SLI game support in recent months and
their hardware will take some beating, we aim to not only test crossfire
but to show you some comparisons against Nvidia in both single and dual
configurations.

http://www.driverheaven.net/reviews/...eatireviewxxx/