Currently running a Sapphire HD 4850 rig and am looking at adding the second HD 4850. (old ASUS DH Deluxe 975X MB) I know that the Crossfire is mucho better now, but what combinations of cards are valid?
1) 2 of the exact same model?
2) 2 of the same brand, aka Sapphire?
3) any 2 HD 4850...