AMD Radeon: Windows 8.1 Catalyst vs. Linux Gallium3D vs. Linux Catalyst
The Unigine Sanctuary performance between Windows and Ubuntu Linux are close to the same when using the 14.3 Beta driver. When using the open-source Linux drivers, there is a measurable performance hit, particularly with the R9 270X on the stock Ubuntu 14.04 LTS configuration where the performance is almost half of the Catalyst driver performance.
The performance comparison is similar with Unigine Tropics. Again, when I'm back from the Linux Foundation Collaboration Summit and have also completed the NVIDIA testing, I will run some tests using the latest Git code (Linux 3.14 or 3.15 at the time, Mesa 10.2-devel) to see how the performance situation changes for those Linux enthusiasts that don't mind upgrading their kernel and user-space drivers.