What inputs and adapters are you using? Reading what others say, you have to get a specific eyefinity approved adapter device, and you must use the same inputs no matter what. If you mix inputs, such as dp dp hdmi you will get tearing guaranteed.
Right now:
Left Screen - DVI Native (deferred)
Middle Screen - miniDP -> DVI Active Adapter
Right Screen - HDMI -> DVI.
however im re-arranging them to be
Left Screen -HDMI-> DVI
Middle Screen - DVI Native (deferred)
Right Screen - miniDP -> DVI
as i only use the right screen in games, on desktop i use left and middle.
right now on the destop, moving windows doesnt tear with DVI Native set to deferred, but I get center screen tearing when watching flash videos.
My Card (Sapphire HD7950 OC) only has 2 miniDP, 1 HDMI, 1DVI. so regardless I'd have to use two different "clocks".