I have three monitors, an HD3200 (igp) and an HD4670. I have all three monitors working, but the two monitors on the HD4670 are one display (:0.0) and the third monitor is a second display (:0.1)... so I have two separate desktops and I can't drag windows between them. (or open firefox on both of them... and a number of other annoyances.)
I thought that this was the best that was possible with current drivers, but I just saw this quote from bridgman in another thread:
Maybe in my hopeful expectation I'm reading too much into that, but "splitting drawing commands across multiple GPUs" sounds like it might mean "drawing half of a window on one GPU and the other half on another GPU".Your best bet for multi-GPU support with 6xx-and-up GPUs today would be fglrx, since it already includes all the functionality for splitting drawing commands across multiple GPUs and screens.
Is it possible to get a third monitor to work like "normal" with AMD cards on linux?