AMD Radeon Gallium3D Starting To Out-Run Catalyst In Some Cases
CoreBreach would only work going back to Ubuntu 12.04.1 LTS, but even so, the results are interesting. With Ubuntu 12.04.1 LTS and Ubuntu 13.04 using the stock open-source Radeon driver, a noticeable performance increase can be found over the past year. With Ubuntu 13.04's updated components there is now in R600g support for HyperZ, the a-sync DMA engine work in Linux 3.8, and an assortment of other Radeon DRM and Mesa Gallium3D improvements over the past year. On Ubuntu 13.04, Xfce was slightly faster than Unity.
The Doom 3 performance on Ubuntu 13.04 is up sharply since Ubuntu 10.04.4 LTS with the open-source driver. (Catalyst failed to work in this configuration for Doom 3 on the Lucid Lynx.) The Ubuntu 10.04 Radeon Mesa driver was incredibly slow with handling GLSL and other OpenGL functionality but at least it's getting better now with Ubuntu 13.04 but it's still not up to scratch with the proprietary drivers.
On Ubuntu 13.04, the open-source stack powering the Radeon HD 4830 is now running at the same speed as the AMD Catalyst binary driver from three years ago! The open-source performance has more than doubled in just the past year for this RV770 class graphics processor.