I heard feedback from media about crossfire performance on R5E BIOS 0603 with i7-5960x with R9 295x2 Crossfire. In game graphic has not smoothly as should be since game intro to game play. But if they use single card of R9 295x2 everything is fine with smoothly graphic.
However, They have test on old system R4E with i7-3960x graphic in game is so smoothly