This started to annoy me. It seems that after exactly of 24-30 hours of using system without restarting it, KWin (desktop effects) becomes slow and sluggish. Every effect (maximaze, glide) has delay. However I found a "fix" for it. Restarting KWin with kwin --replace command. Before restarting Kwin Xorg uses about 100mb of ram and has a higher CPU usage than usual, and after restarting KWin Xorg drops to 70mb of ram and everything is back to normal and effects are smooth again.

Can someone help me and explain me why this sluggines happens?

I am using Kubuntu 10.10, KDE 4.5.3, Catalyst 10.11, Qtcurve style, Oxygen decoration animations turned off, Texture filter nearest (fastest).

Hm, no explanation, but worrying.

I suppose you could cron kwin --replace and have it run every 12 hours or so...

Which Desktop Effects do you use? In particular, you may want to try blacklisting the Lanczos filter, or disabling Blur.

See http://blog.martin-graesslin.com/blog/2 ... n-effects/ for information on how to blacklist.

These appereance efects are turned on: glide, shadow (I turned off oxygen shadow), login, taskbar thumbnails, logout, translucency, highlight window, minimize animation. Rest of effects everything default except present windows turned off and dektop cube turned on.

If you disable all these effects, then incrementally re-enable them, can you determine if a particular effect causes this?

I will wait for slowdown to happen again and then I will turn off every effect one by one and try to find out which desktop effect if any is causing problems.

I couldn't find out what is causing the slowdown. Then I deleted kwinrc file and restarted kwin. I thought it solved the problem but after two days and 8h of using system without restart slowdown came back. There is a lag in every effect and xorg is eating much more cpu than usual. The problem disappears when I disable and than enable desktop effects or when kwin is restarted.

Probably is fglrx driver to blame, bacause friend of mine is using kde 4.5.3 for 8 days straight and has no such problems on intel graphics.

schnelle wrote:I couldn't find out what is causing the slowdown. Then I deleted kwinrc file and restarted kwin. I thought it solved the problem but after two days and 8h of using system without restart slowdown came back. There is a lag in every effect and xorg is eating much more cpu than usual. The problem disappears when I disable and than enable desktop effects or when kwin is restarted.

Probably is fglrx driver to blame, bacause friend of mine is using kde 4.5.3 for 8 days straight and has no such problems on intel graphics.

There could be a memory leak somewhere, probably driver related. Have you tried with the free driver?

No I didn't. Radeon driver is not an option at the moment because it doesn't have power managment and kwin 4.5 performance with radeon driver is just terrible on my laptop (was fine in 4.4). I will be patient and wait for kde 4.6 I hope then I wont have this problem with fglrx driver.

schnelle wrote:No I didn't. Radeon driver is not an option at the moment because it doesn't have power managment and kwin 4.5 performance with radeon driver is just terrible on my laptop (was fine in 4.4). I will be patient and wait for kde 4.6 I hope then I wont have this problem with fglrx driver.

Well, I don't know about this problem but to me kwin in 4.6 is... *amazingly* fast. It's like a whole new desktop experience (running on intel gm945).

Regards

Yes, KWin 4.6 is much better. I tried KDE 4.6 beta 1 and even with free radeon driver effects were smooth (well I had to turn off oxygen animations)

I can confirm that I don't have problems anymore in KDE 4.6

I can also confirm this. Also on KDE 4.6. But it is much better since KDE 4.6. On the other side my hardware is very low end (atom/ion).

I had the effects especially when running kdevelop. I was not able to see an loss of resources like ram or static CPU usage. It felt like the system looses it's performace. Maybe there are some actions on graphics adapter started and never stopped.

Yesterday I could inverstigate the loss of performance again. Within KDE4.6 the plasma process was consuming 40% of the CPU without any actitivies and the xserver also took too much for an inactive desktop. So there is a different behaviour regarding this problem on KDE 4.6.

[Not exactly your case] Shuttle XS35GT (Atom D510, Ion2) under Kubuntu 10.10; 1920x1080 via HDMI.

Poor video reproduction, also slow interface. I followed the advice of disabling "BLUR" and then I had the desktop I was looking for for a time. Blur seems to be a major issue for some low powered platforms.
THX there for the good advices.