Proprietary vs. Linux Git, Mesa 11.2-devel, DRI3 For R600g/RadeonSI

Following this week's OpenGL 4.1 R600g benchmarking with that newly-enabled OpenGL 4 support, I set out to run a larger hardware comparison on both the R600g and RadeonSI drivers as part of our year-end 2015 Linux benchmarking. In this article are tests of seven AMD Radeon graphics cards tested on the proprietary driver compared to the latest open-source driver stack -- with extra steps of enabling DRI3 rendering and also using the latest AMDGPU PowerPlay code.