3d mark score lower in crossfire.

Well, from what I've read around the forums, 7850/7870s don't do so well in crossfire.

And your motherboard doesn't support true crossfire. It's only there for multiple displays. One lane is running at 16x, whereas the other is running at 4x.
 


It's not a 7870. It's a tahiti card.

Also it shouldn't do this bad. In furmark I can see the scaling but not here.