Ok, let me clarify my earlier inaccurate statement about CRTCs. Consider a computer with one physical GPU that has two physical video ports. That physical GPU has two physical CRTCs attached to it. In both zaphod and nonzaphod mode, the host runs one instance of the Xorg process. The difference is that in nonzaphod mode, Xorg "presents" one GPU with two CRTCs, whereas in zaphod mode, Xorg "presents" *two* GPUs, each with a single CRTC. I want to run xmonad in the latter mode. Mike correctly pointed out that the "obvious" way to run xmonad in zaphod mode is to change /etc/X11/Sessions/xmonad to the following: DISPLAY=:0.1 xmonad & # Managing screen 1 DISPLAY=:0.0 xmonad # Managing screen 0, exit to exit X. Unfortunately, that doesn't work. Mike points out that some finagling might be necessary to get this to work, but after several hours I was unable to find the right finagling. I *conjecture* that xmonad does not support zaphod. If anyone on this list has managed to get zaphod to work, please let me know. Thanks! mar