With the latest OpenArena release, which uses GLSL and other improved rendering functionality compared to the earlier releases of this ioquake3 game, the Catalyst driver on this R700-class hardware is four times faster. OpenArena at 1920 x 1080 with these visual settings is not even at a playable frame-rate for the Radeon Gallium3D (R600g) stack.
The non-demanding World of Padman game is at least playable on Radeon Gallium3D with the Radeon HD 4770 with frame-rates above 100 FPS, but meanwhile Catalyst 12.3 is pushing out more than 300 frames per second on the same hardware. In moving from the Ubuntu 12.04 LTS packages to the Git + tweaked configuration, the frame-rate goes up by 17%. Another problem though with the open-source drivers is that most Linux desktop users cannot easily upgrade their open-source drivers without upgrading key components (i.e. the Linux kernel) that may end up borking other areas of their system and is not officially endorsed by Canonical and other distribution vendors. For the PCI Express 2.0 and ColorTiling tweaks, those options also are not widely known aside from with Linux enthusiasts frequenting Phoronix and enabling these options requires manually editing some system configuration files.
The Reaction Quake 3 frame-rate more than doubles when moving from the Ubuntu 12.04 LTS stack to Git from yesterday with the Radeon performance tweaks, but the Catalyst driver is nearly 15 times faster.