Kwin Slowing System Down

[setanta]

Hi, I installed Sabayon 10 KDE a few weeks ago and really like it however from time to time the system starts lagging and slows steadily to a snails pace. It looses all responsiveness so when I click on the menu it takes several seconds for it to load then scrolling through to the log out button takes several seconds. Once I log out and back in all is well and the desktop is as it should.

It seems to me that the problem might be Kwin, if I open the system monitor when the system slows it shows Kwin cpu usage running at 18%, when the system functions normally this is not the case.

My system is new, 64bit version - 8GB Ram on a quad core machine, I dual boot with Windows and never a problem on Windows like this. Although I much prefer to use linux.

Any suggestions would be appreciated as I would like to continue using Sabayon KDE...

Although I have used Linux for 2 years I am not that technically minded.

Many thanks

[Fitzcarraldo]

Sounds like it might be Nepomuk indexing. Try switching it off: System Settings > Desktop Search and disable Nepomuk Semantic Desktop (tagging and rating of files), Nepomuk File Indexer (searching of files by content instead of just by name) and E-mail Indexing (full text search in e-mails and their attachments).

[setanta]

I appreciate the post, I followed your instructions and will feedback on here. Hopefully the issue is solved.

[setanta]

I spent 1 hour working on the machine tonight and it stared to slow down in the same way again, Kwin was running at very high cpu usage. I wonder what else could I do.

[Fitzcarraldo]

Does your machine have an NVIDIA GPU?

[setanta]

Yes it does.

[Fitzcarraldo]

I thought so. Various versions of NVIDIA drivers and KWin have not worked well together, and the common effect is high CPU usage. I'm not sure whether the bug lies in the NVIDIA driver or in KWin, but my guess is the former. If you google e.g. "KWin NVIDIA CPU" you'll find plenty of posts about this problem. You'll even find posts about it in the SL Forums, if you search.

You may find that if you disable compositing in KWin then the heavy CPU usage will not occur. To try that, you can use the KWin default shortcut Alt-Shift-F12 if it works, otherwise see my blog post Toggle KWin compositing on and off easily from your Desktop for other ways to do it.

[setanta]

Many thanks, I disabled desktop effects and will see how that goes.