You need to patch your xorg server with http://cgit.freedesktop.org/xorg/xserver/commit/?id=7ecfab47eb221dbb996ea6c033348b8eceaeb893 (glx: Add support for the new DRI loader entrypoint.) Now it is fast because it doesn't use your graphic card at all :) Regarding your issue with mplayer please see this bug: https://bugs.freedesktop.org/show_bug.cgi?id=71448