Radeon Vulkan Driver Benchmarks: AMDVLK 2018.4.2 vs. AMDGPU-PRO 18.40 vs. Mesa 18.2/19.0
For Thrones of Britannia with the low quality visuals, the Polaris performance on the RADV Mesa code was actually faster than the official AMD Vulkan releases. For the R9 Fury on Mesa 18.2.4 it was also faster than the other Vulkan driver options, but for the latest Vega hardware the performance still sides with the AMDGPU-PRO/AMDVLK Vulkan support.
When pushing Thrones of Britannia with extreme quality settings, on all three graphics cards the performance sided with the official AMD Vulkan driver options.