Yesterday I published benchmarks showing the AMD Radeon graphics being much faster on Linux 3.12. Ten graphics cards were benchmarked and many of them were showing rather remarkable OpenGL frame-rate performance improvements when moving from the Linux 3.11 to Linux 3.12 Git kernel. This large comparison came after benchmarks I did this weekend on a single Radeon HD graphics card showed the Linux 3.12 kernel delivering the best performance of any recent kernel release. The only thing was, this AMD Radeon performance improvement baffled the upstream developers. The AMD developers were taken off-guard and didn't have an explanation why the Linux 3.12 kernel performance is faster... Now thanks to automated testing and bisecting by the Phoronix Test Suite, I have an answer.