Consider the Anand review ... He hasn't figured out yet how two graphics cards video signals are routing to three TB controllers. But consider connecting 3 4k displays to the D300's, for example. Without Crossfire one chip will have to drive two displays, while the other gets an entire display to itself. Can a single D300 handle two 4k displays? Even if it can, that seems like an undesirable asymmetry. I wonder, is it possible that OS X has quietly enabled Crossfire? Or are there tests that have conclusively proved it hasn't? It also seems odd that Apple enabled Crossfire X on Windows, Anand seems convinced they plumbed wires for this, not via DMA. They don't usually give us gratuitous features like this. Regardless, how are they routing the video signals across TB?