With R600g Now Supporting OpenGL 4.1, See How The Open-Source Performance Compares To AMD Catalyst
When it comes to the Counter-Strike: Global Offensive performance, which doesn't need OGL4, the two cards were quite competitive against the closed-source driver. The Radeon HD 6870 on the open-source driver was in fact faster than Catalyst while the HD 6950 performance was at 85% the speed of the binary blob. In past articles we have found the HD 6950 Cayman GPU to be not as well optimized as the HD 6870 on the open-source driver, likely due to not as much tuning for VLIW4.
With the BioShock Infinite game, the HD 6950 performance on the open-source driver was about half that of the Catalyst driver. The HD 6870 couldn't run this game on the open-source driver due to lacking OpenGL 4.1 support.
The DiRT Showdown racing game is another new Linux title this year and it requires OpenGL 4.1, thus only allowing the HD 6950 to compete on open-source. Here, the R600g performance was running at the same speed as Catalyst!