see this video http://www.youtube.com/watch?v=cbww3dhzK0M
although i assume it will bottleneck them Fps.... i wouldn't suggest it.
ah ok thanks a lot bud, Linus knows his stuff. Although I do like PhysX and what it does with the emersion of games; however, I do not think it's worth the bottleneck. I will be sticking with my r9 280x toxic purchase to see if mantle provides a decent margin for bf4 and other future games it may be compatible with. So thanks again with the reply.