Valve clarified that when it comes to which version of a game to run on steam deck, the native incarnation of Linux will be used – rather than the Windows game via Proton – if it makes sense to do so. In other words, if the Linux native port works fine.
There was some confusion around this because some eagle-eyed folks discovered that Portal 2, one of Valve’s own games that was ported to Linuxdropped on SteamDB as being recommended to run on the Steam Deck via Proton (i.e. the Windows version, facilitated by the compatibility layer, Proton, to run on SteamOS which is, of course, a Linux-based operating system).
How Games on Linux pointed out, however, that this was actually just the case because of the way Valve implemented testing these different versions in the early days of working on software compatibility for the Steam Deck.
Valve explained, “Initially, there were a limited number of titles that were tested via Proton before Linux before we made some policy changes. Since then, all these titles are back in the queue for further testing using their Linux builds.”
And if these builds of Linux really work robustly on Valve’s portable PC, then the native version of Linux is recommended.
On a developer document detailing the compatibility review process for the Steam Deck, Valve further explains: “By default, we will test a Linux version if it is available. If the Linux build fails the compatibility tests or has significant issues, we will test the Windows build of your game running on Proton. Our goal is for customers to have the smoothest experience possible on the Deck, so we will send the most favorable set of test results.”
Analysis: Sounds like a plan, but what about these nuances…
This seems like a fair enough way to decide which way to go when any game actually has a native Linux port. However, problems can arise in the verification process when there are nuances such as, for example, PC player (which flagged this) noted, those seen with Borderlands 2, which might have a native version of Linux, but the final DLC doesn’t (so it wouldn’t work).
Or, to take another example, a Linux version might work better, but it doesn’t have the latest updates and tweaks (maybe bug fixes, additional content) for the game that the Windows version does. How deep would the testing process be in these cases and whether these extra factors would be considered – well, the concern is obviously that some of those finer points might be missed.
Also, if the Linux compilation works fine, but the proton The version offers, shall we say, slightly better performance, which may never be noticed – as Valve notes, it won’t pass the test of the Linux incarnation if it’s solid in terms of compatibility and doesn’t present any serious issues.
Of course, you can still run native Linux or the Proton spin of a game as you wish, but less tech-savvy users will clearly go with Valve’s default choice, so it could end up getting worse if any of the above type of gremlins are encountered.
There are a lot of factors in the compatibility stakes for the Steam Deck and there will undoubtedly be a lot of work to be done on this software side of the equation after launch.