2900 and 3870 crossfired

[eric66]

'As shown in the graphs above, we did see performance increases over single card mode when using the mixed card CrossFire. In the case of Call of Duty 4 the gain was nowhere near that of true 3870 configuration but it did make our tested settings playable. World of conflict was much more impressive with a doubling of minimum framerates over a single 2900 XT.'

http://www.driverheaven.net/reviews/3870-XXX/mixed.php