Performance issue with X11

[Patrick O'Callaghan]

I've recently noted that window behaviour is sluggish, particularly
noticeable in scrolling, drawing dialog alerts and switching desktops.

A couple of months ago I ran glxgears and got an average of 750 fps. Now
it's 150, i.e. 20% of what it was. The same result occurs under KDE and
Gnome.

I'm on F9 with KDE 4.1.2 and Xorg-xll-* updated from
updates-testing-newkey. The machine is a 64-bit Core 2 Duo with 2GB RAM
and an Intel 965 video chipset (i810 driver) on an Intel mobo. The
display is a 19" LCD in landscape mode, 1440x900 resolution. Desktop
effects are turned off.

I'm also seeing repainting errors, specifically when moving a window
against the desktop background, which doesn't repaint until I click on
it.

poc