I'm running Ubuntu 12.04 and I have two nVidia quadro 2000 video cards, each with two monitors plugged in (all 4 monitors are identical). Now I have the latest nVidia drivers, and I'm trying to use the nVidia control panel to use all four monitors, and I can't get it to work. Currently, my configuration is using TwinView to have 2 monitors per X screen. This doesn't work well because either i turn xinerama on, and nothing appears on the screen when I start a X session with Compiz enabled. Things only work in Ubuntu 2D. i turn xinerama off, and compiz works, but now, I cant drag windows between the two screens and i have no idea how to start applications in the other screen. Is there a better way to configure my four monitor setup? Is there a way to get both GPUs onto a single X screen?