Don't know if this is an Ubuntu or KDE related question. I've been using KDE 4.2 in Kubuntu 8.10 from kubuntu-experimental for quite some time now. And it felt really good.

Yesterday I upgraded to Kubuntu 9.04 which has KDE 4.2 as well, but now it is super slow. Especially switching windows takes about half a second. It doesn't seem that there are any other desktop effects activated as the ones that were activated before.

I also posted a reply to this post: http://ubuntuforums.org/showthread.php?t=1143535
This user seems to have the same problem.

I also have this problem on Kubuntu 9.04. Under GNOME, the Xorg process is normal (hardly using any CPU), but logging into KDE, Xorg is pegged at about 20% CPU or more all the time. Do you see this as well? It doesn't make any difference whether desktop effects are enabled or not.

I've seen bug reports about slowness with the latest Intel drivers, but I'm using nvidia and I don't think it's a driver issue, since GNOME runs fine.

If you have the calendar plasmoid enabled, try removing it.

bcooksley wrote:If you have the calendar plasmoid enabled, try removing it.

I don't have that enabled.

But I think what I'm seeing is just a konsole problem, probably this bug:

https://bugs.launchpad.net/ubuntu/+sour ... bug/355870

i.e. konsole's text output is really slow and sucks up CPU time. xterm or even gnome-terminal is normal.

foobar wrote:I also have this problem on Kubuntu 9.04. Under GNOME, the Xorg process is normal (hardly using any CPU), but logging into KDE, Xorg is pegged at about 20% CPU or more all the time. Do you see this as well? It doesn't make any difference whether desktop effects are enabled or not.

I've seen bug reports about slowness with the latest Intel drivers, but I'm using nvidia and I don't think it's a driver issue, since GNOME runs fine.

Yes, I've the same problem always ~20% CPU for Xorg.
Where did you find the bug reports with the Intel drivers?

[quote='bcooksley']If you have the calendar plasmoid enabled, try removing it.[/quote]
Nope, I'm not using that.

For people with on-board Intel graphics hardware: I just found this and it actually helped a lot. https://wiki.ubuntu.com/ReinhardTartler ... riverTo2.4