Hi there, Time to get rid of the stuttering window animations of my Mac Pro. Both my additional displays (Dell 2007FP) show very slow window animations, watching videos also lags. The centre display (30" ACD) is perfectly fine. The displays themselves are not the problem, I've tested them with my laptop and they are fine there. I also tested all graphics cards configurations possible: - only a single graphics card with one or two displays connected - 30" to 4870, 1 20" to 4870, 1 20" to GT120 - 30" to 4870, both 20"s to GT120 The latter is what is running now (and what I'd like to keep it). I really don't have any clue what might cause the lag. Did anything change in OS X? I never had this kind of problem with previous display setups. Everything was perfectly lag free. Any recommendations?