Scrolling performance

["Clemens Eisserer" <linuxhippy gmail com>]

Hi there,

I recently updated to OpenSuSE 10.1 since some people suggested that
Eclipse/GTK's performance is better with gtk 2.8.
My machine is a Athlon 1000 with 512mb SDram and a GeForce FX5200 with
latest NVidia binary drivers, renderaccel enabled.

GTK applications tend to be very unresponsive compared to other toolkits:

- Slow expose reaction. If I move a window above e.g. gtk-demo I see a
repaint-lag of about 2-3cm.
- Slow scrolling. Even fast scrolling inside of the filechooser is not
smooth. I can see
scrolling srtifacts which look like caused by asynchronous repainting
of the scrolled area.
- Slow layouting, especially for Text composnents: Moving e.g. the
vertical splitters of gftp (one pane a table as content, other table
is empty) is done with about 5fps.
Even my old P233 with Windows2000 can do compareable GUI operations
without any problems. Also reslayouting/repainting windows after
window-size change is slow.
- Sluggish Menu-behaviour. In gftp I can feel a ~400ms lag, therefor
it takes about 400ms for the menu to catch up to my mouse-pointer if I
move with about 500pixel/s.
- Eclipse in general is just _very_ slow at all. If large popup menus
go away you see the background about 300-500ms repainting itself.
Netbeans (Swing based) is way faster, only after start its slow (till
the java JIT compiled the hot spots).

I know this is an opensource project, I know if something bothers me I
can grab the code and enhance it or dontate some money to make someone
else fix my problems.
However I still go to school and currently have to do my diploma -> no
money, no time.
I know its unpolite to post such problems to the list, but bad
performance has been discussed since ... I guess the 2.0 release. I
still remember many projects refusing to upgarde with tables of
micro-benchmarks.
Till a long time improvements are promiesed, fast paths in pango,
enhanced speed of cairo, better repaint handling and whatsoever.

If I start a application which links against GTK-2.8 _feels_ exactly
as good damn slow as GTK-2.0. The I start a GTK-1.2 based problem and
can't trust my eyes ... what happend to GTK. At times of GTK-1.2 I
preffered GTK since it felt a bit faster than QT-2.x but now QT is
lightening fast compared to GTK-2.x not talking about high-performance
libraries like FOX or FLTK. I used Mozilla/GTK1.2 builds as long as
they were available, since even mozilla slowed down by only using
GDK(2).

I just don't get it why I need a 3ghz PC to not see repaint lags or
5fps layout updates.
These things worked years ago ten times better than now (and no, this
are not themes. GTK-1/QT-2 were themed too with tons of pixmaps). What
has happend?
I guess performance regression testing is something never here has heard of :-/

And where to start getting my hands on? I just can't work with this
crap anymore, but since GTK is on the way to be used as the default
toolkit ... it seems there's no way arround it.
Which profiling tools do you recommend? Do you think using the intel
compiler is worth a try?
Where does all the time go to? I've done some sysprof-profiling and
its shows than pango is not the evil. Are maybe the repaint
algorythmns not optimal, repainting too often too large areas/hidden
components?

Sorry for wasting your time and your energy, a frustrated Clemens