Hello,

I have the following problem when I enable compositing in KWin: When compositing is enabled at first most things are fluid (framerate is around 58 fps, but opening a new tab in Opera for example leads to a significant temporary drop in framerate on my system). But after a while the framerate drops significantly (the fps monitor is showing me around 2-3 fps) and stays low.

I have a x1400 card with 128 MiB of dedicated memory. I’m running mesa git with r300g and kernel is 3.3.1. CPU usage is around 10%.

Another problem I have is that the sound stutters when I'm watching full screen Flash videos without compositing enabled.

I would like to help finding the cause of these problems if somebody can give me some hints on how to find out the causes of the problems.

Would the bug tracker be a better place for tracing these problems?


Best regards
Martin

I don't really know Raedon gpu's (the x1400) or their drivers but I believe the r300g is the opensource driver and you will be better off using the closed fglrx drivers. your distro should have instructions on how to switch

you could try changing to compositing type Xrender instead of openGL (in the destop effects advanced tab)

google01103 wrote:I don't really know Raedon gpu's (the x1400) or their drivers but I believe the r300g is the opensource driver and you will be better off using the closed fglrx drivers. your distro should have instructions on how to switch

For ATI this is a bad advice The free drivers are much better and it is quite likely that the proprietary does no longer support the chipset (not sure which of the legacy is dropped).

Yes, the flgrx drivers won't work anymore because this card is not supported by the current flgrx driver anymore and my xorg server is too new to use an older package of flgrx.

Can you check if your system is swapping in any manner during the operation of compositing?

Also, do you have any other OpenGL applications running when using KWin?

Interestingly enough I'm not able to reproduce the problem now. I have disabled all plugins except Dashboard, Screenshot, Startup Feedback and Resize Window. Probably it was a combination of an enabled plugin and some special circumstances. I will check back here if the problem occurs again. So far it running smoothly.

But I am still interested to find the problem with the sound of full screen videos when compositing is disabled. If anybody could give me a hint here how to find out what the problem could be it would be appreciated very much.

How do you connect your computer to your speakers? Is it via a standard headphone cable, or is it via something routed through the graphics card such as HDMI?

It's a standard headphone cable. It's a Thinkpad T60 I'm working on which hasn't any HDMI output.

If you try playing with a different application, does that work?

The sound problem I have is only with full screen flash videos. Playing a video in full screen with any of the usual players (vlc, smplayer, totem,...) works fine.

that's part of the reason why ppl. swear on flash ...

to make this sure: it stutters WITHOUT compositing, but WITH compositing everything is fine?

- try the xrender backend (to see whether the compositor or the GL context helps to "resolve" this)
- check CPU load while playing such video (switch to VT1)
- does it happen with flash from all browsers? (eg. chromium afaik comes with its own flash plugin)
- and most important: if you've pulseaudio installed and enabled, shut it down - then restart the browser and try again

Seems like somewhere between some system updates this problem was solved too.

I'm happy that the problems seem to have been fixed somewhere but it is a little unsatisfactory to not have found the root of the problems. I would still be very interested on how to debug such problems if they should occur again.

stuttering sound?
check cpu load and any IO load, get all sound daemons and layers (pulse / phonon) out of the way and check their config as well as the alsa one.
good chance is also usage of the alsa oss software emualtion instead of the kernel module (and of course a client using oss)