AMD RadeonSI Gallium3D Performance For 4K Linux Gaming
The Radeon graphics cards that were tested (based upon those within my possession) included the Radeon HD 7850, HD 7950, R7 260X, R9 270X, an R9 290.
This benchmarking was done with Ubuntu 14.10 x86_64 but of course doing manual upgrades for the Linux 3.17 kernel and newer user-space / Mesa code. All benchmarks were carried out via the Phoronix Test Suite.