Trying Out The Experimental AMDGPU OverDrive Overclocking With The R9 Fury
See that earlier article for more details on this AMDGPU OverDrive support. This weekend I also spun up an Ubuntu/Debian kernel of the Radeon/AMDGPU 4.8 WIP code but again be forewarned that this support is currently experimental, only allows changing the core clock speed for now, and is limited to supporting Tonga/Fiji/Polaris.
With the playing around I've done with the AMDGPU OD code on an R9 Fury (Fiji) graphics card, it's worked out without any major issues. The highest overclock I was able to achieve with my Sapphire Radeon R9 Fury was an 8% overclock to its core frequency -- anything higher would result in games locking up.
Over on OpenBenchmarking.org are a few benchmarks showing the AMDGPU R9 Fury performance when setting the pp_sclk_od to 8 relative to the stock performance on this open-source DRM driver.