compiz default inclusion causes performance regression in gutsy

[Jeff Fortin Tam]

Binary package hint: compiz

I did these two tests (unscientific benchmarks: using my wristwatch's chronometer) on a cold boot on an acer travelmate 2428 laptop (1.8 GHz pentium M, 768 MiB of RAM, 5400 rpm drive).

45 seconds = GNOME login time with "normal" desktop effects activated in the Appearance settings
30 seconds = GNOME login time with no desktop effects

This is a 50% performance regression. It is HUGE. It nullifies almost entirely the work that has been done so far with optimizing GNOME.

I think there is some serious optimization to be done in here if compiz is to be activated by default.

This would explain why the Live CD took so long to load too, compared to dapper's (note that my benchmarks were done on a fully installed system, not the live CD; I expect the performance gap to be actually magnified on the liveCD).

[Gert Kulyk (gkulyk)]

II can confirm this on a HPNX6110 with i915GM and 512MB Ram. Desktop-effects enabled by default on the live-cd (latest tested 2007-09-10) causes a nearly unusable desktop. Installed system is slower than it should, too (and not yet tested, but I suggest there will be effects on battery-usage) . Furthermore there is no gui to turn specific plugins on or off installed by default (AFAIK even not in main-repros), all settings have to be changed via gconf - not very user-friendly.

People should be asked if they want to have desktop-effects when they log-in the first time, describing that there may be performance-regressions and other issues (and where and how to en-/disable it later on).

[Siegfried Gevatter (rainct)]

Gert: As a side note, you can enable/disable/configure individual plugins using the application compizconfig-settings-manager which is available in universe.

[Travis Watkins (amaranth)]

As drivers get better compiz will start faster, other than that there is nothing to be done here.