Valve's Pierre-Loup A. Griffais has begun publicly listing known issues with AMD's Catalyst Linux graphics support.
Via this Steam Community discussion page, known issues with the AMD Linux graphics support as it pertains to SteamOS are listed. The page is to be updated as Valve discovers more issues.
The issues listed right now include black/flickering screen when full-screen mode is enabled for certain games, lower performance compared to desktop distributions, and crackling sound over HDMI. Of course, already in the comments are many Linux gamers chiming in with their AMD Linux graphics troubles.
While we routinely carry out Ultra HD (4K) Linux graphics/gaming benchmarks at Phoronix, it's generally been conducted with the proprietary NVIDIA and AMD graphics drivers since the open-source drivers traditionally have had a challenge on performance even at 1080p. However, thanks to the maturing open-source Radeon driver stack, it's possible with higher-end AMD graphics processors with the latest open-source Linux driver code to begin running at the 4K UHD resolution of 3840 x 2160.
You might be surprised to learn that outside of work, bringing up three children and a dog and writing about Linux that I try to find time for other hobbies such as being a navigator at classic car rallies and playing old computer games.
This article looks at the options available for potential retrogamers using a fairly standard Linux Mint or Ubuntu setup.
There are already specialist Linux distributions available for playing computer games such as Puppy Arcade. If you just want to play games casually then running a whole distribution to do so might seem a bit overkill.