Window scrolling (e.g. firefox, thunderbird) very slow

Hi,
I've got the same problem here and I have to say that it's annoying. But it doesn't affect only firefox. If I scroll any window with slightly more complicated content cpu usage goes up to 50% on both of cpus, I use intel drivers here and it used to work like a charm in gutsy.

Of course, It's not only about scrolling.

No certain compiz plugin doesn't cause this problem.

Any idea what I can do to find the source of a problem?

pheeror@minerva ~ $ ps aux|grep compiz
pheeror 6297 0.0 0.0 3944 620 ? S 22:14 0:00 /bin/sh /usr/bin/compiz --sm-client-id default0
pheeror 6359 0.7 3.9 215252 40348 ? S 22:14 0:17 /usr/bin/compiz.real --ignore-desktop-hints --replace --indirect-rendering --sm-client-id default0 ccp

On my system (amd64, intel 82G33/G31) I can workaround the problem by setting
 Option "AccelMethod" "XAA"
in Xorg.conf. Of course, XV doesn't work with this option.

more info: https://bugs.freedesktop.org/show_bug.cgi?id=12778

Actually, this bug is not compiz problem. It's bug in intel and ati drivers, thus you have thought it's compiz related.
For intel drivers, relevant bug is https://bugs.launchpad.net/xserver-xorg-video-intel/+bug/177492

another nice "coincidence" is that suggested solution (adding Option "MigrationHeuristic" "greedy", see 'man exa') should work for ati cards as well.

MigrationHeuristic Greedy works for my intel laptop but not my ATI desktop.

The bug 88696 seems relevant for the ati problem.

confirm: slow scrolling on FF3 and thunderbird with compiz enabled>>> nvidia 8400gs / ubuntu hardy

Confirmed: slow scroll with FF3 RC1 when compiz enabled, MigrationHeuristic Greedy doesn't work with nvidia

Confirmed: When Compiz enabled, Firefox isn't usable anymore. Core 2 Duo, Intel GMA 950

This is not a dupe of #177492, that one is ATI-specific whereas this one concerns all video cards.

Also, it has clearly been confirmed too many times.

Another update. Using this command I was able to noticeably improve the scrolling performance w/ compiz on nvidia:
nvidia-settings -a InitialPixmapPlacement=2 -a GlyphCache=1
(you may also try InitialPixmapPlacement=3)

Now I'm getting roughly 50% System and 50% User CPU usage, as opposed to 100% User CPU usage without this command. Thought this was worth mentioning.

Still getting this issue in Karmic on one of my rigs, AMD Athlon64 3200+ with an NVidia 7300GT. I'm running the 185 NVidia drivers and Firefox 3.5.

I've also tried 190b drivers with Firefox 3.6, but no luck.

This is becoming tiresome. Something as basic as browsing should just work, especially given that it used to just work.

There was been several different video cards mentioned in this bug and all except nvidia seem to get fixed with xorg.conf changes. If anyone is still having this problem please file a new bug against your video card driver with details on your video card.

This is a bug in the drivers.

I only have issues with Firefox. If I am using no other programs except Firefox, RAM is at 89% contstantly. Firefox lags in scrolling and it seems to be something with page load. Once the page is entirely loaded, scrolling is fine.