For your viewing pleasure today is a 13-way AMD Radeon graphics card comparison when testing out the open-source Radeon Gallium3D drivers on the wide spectrum of ATI/AMD GPUs while looking at the performance for Valve's Source Engine with Counter-Strike: Source and Team Fortress 2. Given the imminent arrival of Steam Machines and SteamOS to push Linux gaming into its long-awaited spotlight, is AMD's open-source Linux graphics driver capable of delivering a reasonable level of performance?
From Ubuntu 13.10, the open-source driver configuration tested was the current best experience possible using the Linux 3.12 kernel (and enabling Radeon Dynamic Power Management; it will be defaulted in Linux 3.13) and using the Mesa 10.0 Gallium3D code that's expected to be released as stable later in the month. For those curious how the open-source Radeon performance compares to the closed-source Catalyst driver for Valve's Source Engine games, that comparison will be saved for a later article on Phoronix. This article is just looking at the open-source AMD Radeon driver performance and not Catalyst since this testing goes back further than the HD 5000 series where the current mainline Catalyst driver support ends. The Legacy Catalyst driver for HD 2000/3000/4000 series GPUs is not compatible with modern Linux distribution releases due to kernel and xorg-server compatibility problems.
Originally, this was going to be an open-source Linux GPU driver comparison of not just AMD Radeon graphics processors but also NVIDIA GPUs with the open-source reverse-engineered Nouveau driver. However, the current Nouveau Gallium3D driver doesn't really work properly for Source Engine, at least when tested with Team Fortress 2 and Counter-Strike Source. I've tried Nouveau on multiple systems but it is always a miserable mess for Source (screenshots below). The lack of re-clocking support so the GPUs core and memory frequencies can properly be set for modern GPUs also makes its performance horrible compared to NVIDIA's official Linux driver. The binary NVIDIA driver works wonderfully for the Source Engine on Linux and I had shared some 10-Way NVIDIA TF2 benchmarks a few days earlier.