While leaked slides indicate AMD was planning better gaming on Linux for Crimson, in the end they really didn't deliver. Even for their mentioned games, when testing various Linux OpenGL games on three different systems the performance was largely unchanged.

For the past six hours since the release of Radeon Software Crimson Edition for Linux, I've been busy running Linux gaming tests on a Radeon R9 290, R9 295, and R7 370 as a selection of modern graphics cards now that they dropped the pre-GCN graphics card support.