Comment 35 for bug 303011

Guys, try "glxinfo | grep render". Most probably you have sw rendering.

For no obvious reason, I couldn't get hw acceleration working. That is
reason of performance drop.

I didn't try compiz with it, gut in glxgears I experienced drom from
~1000 fps to ~300 fps.

However, upgrading by edgers repository brought hw acceleration back,
glxgears improved to ~450 fps and Compiz runs pretty smoothly to me.
Although some minor glitches are visible as performance is still below
that I had in Intrepid.

So, try to upgrade packages with edgers repository. It should help.
But don't expect too much.