Phoronix have had a chance to test out the refreshed Polaris RX 580 on the Linux 4.11 kernel and Mesa 17.1-devel, initially the AMDGPU-PRO 17.10 driver update was not included thanks to interesting timing.  The performance deltas are as you would expect, a slight increase in performance that is relative to the increased clock speeds, just as when run on Windows.  They also had a chance to try overclocking the new card, AMD added support for overclocking GCN 1.2 and newer cards on their proprietary Linux driver in 2016.  They managed to increase the core by 6% without running into stability issues however when they overclocked the memory, they saw serious performance decreases.  Check out the steps they tried along with the results from the overlocked GPU here.

"Yesterday I posted the initial Radeon RX 580 Linux benchmarks while now with having more time with this "Polaris Evolved" card I've been able to try out a bit more, like the AMDGPU Linux overclocking support. Here are the ups and downs of overclocking the Radeon graphics card under Linux."

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