Comment 34 for bug 798868

Revision history for this message
Daniel van Vugt (vanvugt) wrote :

Experimental fixes for this and related performance bugs are now available
for testing in ppa:vanvugt/compiz and ppa:vanvugt/unity. For the best
results I recommend trying both together. But testing them individually is
useful too.

IMPORTANT NOTES:

  * The fixes in ppa:vanvugt/compiz REQUIRE that "Sync To VBlank" is ENABLED
    in CompizConfig Settings Manager (OpenGL section).
    This is the default setting when Ubuntu 11.10 is installed.

  * When using ppa:vanvugt/compiz you should DISABLE the workaround
    "Force full screen redraws (buffer swap) on repaint" in
    CompizConfig Settings Manager (Workarounds section).
    This is the default setting when Ubuntu 11.10 is installed.

  * I don't claim to have fixed all tearing. I only claim that the amount of
    tearing in oneiric with the fix is no longer worse than in natty.

  * nouveau: If you are using the "nouveau" driver for NVIDIA chips you will
    need to enable sync-to-vblank support in the driver options because
    nouveau has it disabled by default. You can do this by editing
    /etc/X11/xorg.conf and adding:
       Section "Device"
           Identifier "My Graphics"
           Option "GLXVBlank" "on"
       EndSection
    Then log out and in again for it to take effect.

  * fglrx (Catalyst): The fglrx driver also disables sync-to-vBlank support
    by default. To fix this:
      1. Open Catalyst Control Center.
      2. Go to 3D > More Settings.
      3. Set "Wait for vertical refresh" to
         "On, unless application specifies".

  * Please don't try using the Benchmark plugin in compiz-plugins-extra
    because it is broken and misleading (bug 898548).

Please leave feedback in the relevant bug reports.

- Daniel

---

ppa:vanvugt/compiz | https://launchpad.net/~vanvugt/+archive/compiz
compiz (1:0.9.6+bzr20110929-0ubuntu6vv2) oneiric

  * Added proposed fix for inaccurate frame timing causing tearing and
    stuttering.
    (LP: #880707) (LP: #888039) (LP: #92599) (LP: #798868) (LP: #876575)

ppa:vanvugt/unity | https://launchpad.net/~vanvugt/+archive/unity
unity (4.24.0-0ubuntu2b1vv4) oneiric; urgency=low

  * Fix major performance regressions due to unnecessary UnityFBO binding
    (LP: #861061) (LP: #880707)
    UnityFBO was being bound even when not required. This caused major lag in
    glPaintOutput, which slowed down all rendering. This was seen in reduced
    framerates in apps (LP: #861061) and significantly worse screen tearing
    with Unity 4.x compared to 3.x (LP: #880707).