Hi. I'm using kde 4.3.1.
When I enable compositing in desktop settings, I get lots of error messages in .xsession-errors (or in terminal, when I do kwin --replace):
WARNING: Application calling GLX 1.3 function "glXQueryDrawable" when GLX 1.3 is not supported! This is an application bug!

When compositiong enabled, scrolling in firefox is slow. Also fps is low while moving windows.

glxinfo says, that server GLX version is 1.2.
My card is mobility radeon x700, driver - xf86-video-ati (r300).

btw compiz works fine.

actually the question was - is glx >=1.3 needed for running kwin compositing?

The GLX warning is meaningless. The said function is required for GL_EXT_texture_from_pixmap support and if the driver says it supports that extension then it means it's safe to use the function. The Compiz developers have already argued this with the Mesa developers and I believe the warning message has now been removed.

As for having slow compositing: Since scrolling in Firefox is slow all I can say is that it's either a bug with the driver or an X configuration problem.

Thanks for your reply.
Is there any way to tell kwin to use "indirect rendering", like in compiz?

note173 wrote:Thanks for your reply.
Is there any way to tell kwin to use "indirect rendering", like in compiz?

in system settings -> desktop effects -> advanced
unclick "enable direct rendering"
maybe also change texture filter to "nearest"

Mine was going slower than compiz, but then I changed it to trilinear instead of nearest or bilinear. After that kwin is now fast, and all of the animations run very smoothly. I'm quite happy with it:)

Here am I again..)
Now I'm using kde 4.3.85 on gentoo. Problem is still here - in 4.1, 4.2, 4.3, and now 4.4 OpenGL kwin compositing doesn't run smoothly (slow scrolling, low fps window moving). No errors in logs, and seems that CPU usage is identical with and without compositing.
XRender works fine (but is very slow with animations).

So how can I debug this problem? Don't even know what might cause it... Compiz forks still fine (well, worked. kde 4.4 has different api so can't compile compiz right now).