I have a ATI proprietary drivers but it makes the Unity 3D very slow except 2D. Like everything works but it runs a bit slow and choppy. You could even see it when you see the loading circles on the Chromium browser. Also it shows choppiness when I have the wobbly windows turned on. Can someone help me fix?
I had same problem, but, however, in my case adjusting compiz settings didn't help a lot.
I also had ATI drivers installed. Then I noticed ATI had JUST released new ones, which are said to have much better supprot for the latest X and Unity. However, ATI released them too late, and they failed to get into Ubuntu repositories.
What I reccoment you is to uninstall the ATI driver (fglrx) Ubuntu installed for you, and get the newest one from the ATI's site: http://support.amd.com/us/gpudownload/Pages/index.aspx
In my case this provided incredible improvement of overall performance. I hope it will help you too!