Timo, By coincidence Michel Danzer and I were experimenting with packages he built sans xcb, see the upstream bug: https://bugs.freedesktop.org/show_bug.cgi?id=10173
What we discovered is that it's definitely caused by xcb, and it's a client-side issue - respawning metacity after changing the packages will trigger the slowness/speedup, without an X server restart. -- Sluggish rendering since xorg 7.2 update https://launchpad.net/bugs/88815 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
