Comment 14 for bug 88918

Since Gutsy seems to be aspiring for compiz-by-default in time for release, having the latest TTM support for Intel (and some ATI) cards is a high priority.

Michel Danzer (and others) introduced new "aiglx-zero-copy-tfp" patches into xf86-video-intel xf86-video-ati, xserver-xorg and mesa, designed to improve performance with compositing managers using EXA acceleration (especially with scrolling). While these patches are already included in Gutsy's packaged versions so far, until the new drm kernel modules are enabled, this new functionality will not work:

/var/log/Xorg.0.log:
(II) intel(0): Unable to use TTM-based memory manager with DRM version 1.6