Comment 9 for bug 359818

Documented at <https://wiki.ubuntu.com/JauntyJackalope/ReleaseNotes#Performance regressions on Intel graphics cards>:

"Users of Intel video chipsets have reported performance regressions in Ubuntu 8.10 compared with previous releases (bug 252094). Many of the issues have been resolved in Ubuntu 9.04, but some remain.

  * Some users have found improved performance by using the "greedy" migration heuristic. This can be done by running "sudo gedit /etc/X11/xorg.conf", and adding Option "MigrationHeuristic" "greedy" to the Device section of your xorg.conf.
  * Alternately, a new experimental acceleration architecture option, "DRI2/UXA", is available for Intel graphics users which our testing has found provides significant performance improvements in some cases, but has also shown risk of severe stability problems. You can opt-in to enable this by running "sudo gedit /etc/X11/xorg.conf", and adding Option "AccelMethod" "UXA" to the Device section of your xorg.conf. Users wishing to maximize stability should stay with the standard default acceleration method, "EXA".
  * If none of the above helps, some users reported success with using an older driver version."

There will be further refinements of the text (in particular, to warn that UXA may make X unusable on some systems), but I think the current text covers this issue. If you think more is needed, please reopen the release notes task.