Hi everyone,

I am experiencing a very dubious issue with Kwin, namely: I have had inconsistent performance when Desktop effects are enabled (Sometimes it is smooth, when not a lot of apps are running. After the system has been running for a while and a lot of programs are open, the effects get choppy and rather annoying, like fingernails on a chalkboard). What I have discovered as of yesterday though is this: glxinfo tells me that direct rendering is actually enabled.

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raymears@raymears-laptop:~$ glxinfo | grep direct
direct rendering: Yes


Whereas when I do a kwin --replace, I get this contradictory information:

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    raymears@raymears-laptop:~$ kwin --replace
    OpenGL vendor string:                   ATI Technologies Inc.
    OpenGL renderer string:                 ATI Mobility Radeon HD 4650
    OpenGL version string:                  1.4 (3.3.10524 Compatibility Profile Context)
    Driver:                                 Catalyst
    Driver version:                         1.4
    GPU class:                              R700
    OpenGL version:                         1.4
    X server version:                       1.9
    Linux kernel version:                   2.6.35

    Direct rendering:                       no

    Requires strict binding:                yes
    GLSL shaders:                           no
    Texture NPOT support:                   yes
    QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: No such file or directory
    QFileSystemWatcher: failed to add paths: /home/raymears/.config/ibus/bus
    Bus::open: Can not get ibus-daemon's address.


So it says it doesn't have access to direct rendering. Is this information actually relevant? Because from within the "Advanced" tab, under the "Desktop effects" configuration screen, in "System settings" I can check and uncheck the box labeled "Enable direct rendering."

And subjectively speaking, i.e. not using any actual benchmarking tool, I see a difference between the two modes. But this is just speculation on my part.

If everything was running using indirect rendering it would explain the ****, inconsistent performance.

Other information: running Kubuntu 10.10, KDE 4.6, on a Vaio with an ATI graphics adapter, using the ATI proprietary driver, installed manually.

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raymears@raymears-laptop:~$ fglrxinfo
display: :0.0  screen: 0
OpenGL vendor string: ATI Technologies Inc.
OpenGL renderer string: ATI Mobility Radeon HD 4650
OpenGL version string: 3.3.10524 Compatibility Profile Context


Any ideas why kwin doesn't play along?

Thanks

EDIT: I have also figured out from KInfoCenter that the whole of KDE is relatively uncertain in regards to whether there is any direct rendering available or not. Screenshot: http://img22.imageshack.us/i/kinfocenter.png/

PS: I have also tried compiz, as a yardstick of sorts, and its performance is sublime. Too bad it's config and the integration with the Desktop Environment are ****.

This possibly means that your card (or more likely it's driver) does not sufficiently support the 3D constructs KWin needs to create it's effects. As such, with the functionality tests having failed, KWin has disabled it's 3D support.

Alternately, it could be that previous crashes have caused KWin to blacklist 3D support on your system. Moving ~/.kde4/share/config/kwinrc elsewhere outside of KDE should fix this however if it is now fully fixed.