Perhaps the current X update has broken my install. At least in 2012-Feb-21 this kernel-rt worked with X and the nv driver. I tried to boot the kernel-rt to build a new module for VBox. # pacman -Qi linux-rt xorg-server xf86-video-nv | grep Version Version : 3.0.14_rt31-1 Today updated: Version : 1.12.0-1 Version : 2.1.18-5 This does work with X 1.12: # uname -r 3.2.9-1-ARCH # pacman -Qi nvidia | grep Version Version : 295.20-3 Anybody using current nv driver with kernel-rt 3.0 or current version 3.2.9_rt17-1 from AUR? -Ralf