How Ubuntu 16.04 Is Performing With AMDGPU/Radeon Graphics Compared To Ubuntu 14.04 With FGLRX
First up is BioShock Infinite, which due to its OpenGL requirements is a game that can't run on the open-source driver stack of Ubuntu 14.04.4 LTS. Fortunately, with the latest Mesa there are the necessary extensions so there is open-source driver support with Ubuntu 16.04. Thus here is just a comparison of fglrx on Ubuntu 14.04.4 versus this Mesa 11.2 + Linux 4.4 (4.5 DRM back-ported) comparison on the supported graphics cards.
Interestingly, the open-source RadeonSI Gallium3D driver with the Radeon and AMDGPU DRMs is faster than the fglrx binary driver on the current Ubuntu LTS release.
At 2560 x 1440, the open-source driver on Ubuntu 16.04 remained faster -- except for the R9 285 where the support was borked. The R9 285 is further made sad by the fact that the open-source AMDGPU driver stack really doesn't work for any performant means on Ubuntu 14.04.4 LTS. With the open-source driver, BioShock Infinite on the R9 Fury was now much faster than the R9 290, which wasn't the case with the binary blob.
While BioShock Infinite was faster with the latest open-source driver than closed-source, this wasn't the same for DiRT Showdown. When comparing DiRT Showdown on Ubuntu 14.04 with the binary driver to Ubuntu 16.04 on the open-source driver (with the 14.04.4 open-source driver also not able to handle this game), the driver performance was decent but the now deprecated Catalyst Linux driver was still faster on all of the graphics cards tested. However, even here for this Xeon CPU that has a turbo boost up to 4GHz, DiRT Showdown still appears rather CPU bound on Linux given the very similar performance between the graphics cards.