Getting the Radeon multi-platform HD 7950 comparison kicked off with the Lightsmark (OpenGL 2.1) benchmark, which is rather CPU limited with modern GPUs and the proprietary graphics drivers, Windows was much faster. The Radeon HD 7950 on Windows 7 with its Catalyst 12.4 driver was 76% faster than the Linux Catalyst 12.4 driver. The Windows GeForce driver was also faster with the NVIDIA GTX 680, but there by just 42%.
When running the Nexuiz game at 2560 x 1600, as the earlier results showed, the GeForce GTX 680 was noticeably faster with Ubuntu 12.04 and the respective binary driver over Windows. For the Radeon HD 7950 on Catalyst, the positions were swapped and the Windows 7 configuration ended up being faster for the AMD graphics card.
For the high-end AMD Radeon graphics card with Unigine Heaven at 1920 x 1080, the Windows and Linux results were very close to each other for this most-demanding OpenGL Linux benchmark.