One of the things that set Valve’s upcoming Steam Deck apart from other PC handhelds is its choice of operating system: the platform is based on Linux, not Windows. Valve’s Proton Compatibility Layer allows games that currently only support Windows to run on Linux without having to port each game individually.
For Linux gamers, the successful launch of Steam Deck could lead to a new discovery of compatibility and a new focus on Linux gaming. A recent article from Gaming On Linux sheds light on Valve’s compatibility testing process and how it’s changed.
Until recently, Valve favored Proton, even though the game already had a native Linux version. Valve’s own Portal 2, for example, recommends Proton running on Ste AMD B, even though its Linux version was released way back in 2014.
Valve has now updated its policies and developer documentation to reflect that it will prioritize testing native Linux versions of games, and will only run games through Proton if they “fail compatibility tests or encounter major issues.”
It seemed like a logical move, but some commenters expressed concern about some Linux ports. For example, Borderlands 2 has a native Linux version, but the game’s latest DLC doesn’t support Linux. Another member of the community mentioned older OpenGL games that might see better performance on the Vulkan API via Proton.
A HowToGeek article published late last year suggested that Linux gamers choose Proton, even if the game has a native Linux port (Linux users can choose from a drop-down menu on Steam).
The author’s reasoning is that most developers don’t consider it a priority when developing a Linux port, the Borderlands 2 DLC issue being a good example. Proton, on the other hand, was critical to Valve’s success on Steam Deck, so they were fully motivated to make sure it made the experience as complete as possible.