Re: Suggestions: What card to crossfire w/hd 4870x2?
Nope. To get the most performance out of an SLI/CF setup, you need identical families of cards. You can do it from different makers, but it's best if you just buy the same card from the same maker to do this with.
Otherwise, your lowest common denominator is where the performance will be based from (i.e. the slowest card, if it works at all)