Hey all,

I use Slackware 14 32-bit with the latest FGLRX legacy driver. The installation went smoothly, no errors or warnings, during boot I'm told that the kernel modules are loaded, all fancy and good.

If I log into KDE with a root account, I don't experience any problems, all animations and effects are smooth. glxgears reports a spectacular 1000 FPS with effects switched on, and even 4-5 times more with effects switched off.

However, when I log into my user account, desktop effects become choppy, and OpenGL games/apps produce uselessly low framerates. glxgears keeps telling that I have 1000 FPS, but the wheels themselves show only ca. 1 frame per 5 seconds. Switching off desktop effects helps, but I'd prefer having the same smoothness as in the root account...

I'm already member of the 'video' group.

Do you have any idea what could be the problem?

Check your X logs, there should be a clue in there.

try add to your xorg.conf section

and try enable debug mode for OpenGL

Ok, I managed to solve it. It was as simple as switching KWin's composite mode from XRender to OpenGL

Thanks for the answers!