AMD Radeon RX 590 Linux Benchmarks, 18-Way NVIDIA/AMD Gaming Comparison
Thrones of Britannia on Linux had just above a 60 FPS average with the low quality settings at 4K and coming in about 14% faster than the RX 580.
The OpenGL GeeXLab was recently added to the Phoronix Test Suite but its performance on the Radeon side comes in quite poor and shows more room for RadeonSI performance to be optimized.