I have also this problem with 945 gm (hp nx7400) using dapper with beryl repositories (1.6.5) and using edgy (xorg 7.1 i810 1.6.5). With 1.4.1 I have ~1700fps with glxgears, with 1.6.5 ~700 fps like you. This should to be fixed prior edgy release....
I noticed errors in my xorg log with 1.6.5 driver of this type: xf86AllocateGARTMemory: allocation of X pages failed Using i810 1.5.0 (compiled from debian package) these errors are not present. ** Attachment added: "edgy xorg i810 1.6.5" http://librarian.launchpad.net/4873548/Xorg.0.log -- performance issue in Edgy with i810 driver https://launchpad.net/bugs/61306 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs