Valve confirmed in an exclusive interview that it is the main financier of technologies that allow games developed for Windows and x86 architecture to be run on devices with Arm processors. The information was revealed by Pierre-Loup Griffais, one of those responsible for SteamOS and Steam Deck, to the website The Verge this Tuesday (2). The company’s goal is to eliminate the need for specific sizes and expand the reach of the Steam catalog to billions of mobile devices and future Arm laptops.
The strategy uses open-source compatibility layers, such as Proton and the Fex emulator, both supported almost entirely by Valve since 2016. The same technology already equips the Steam Frame headset and can be applied to Android smartphones without official modification of the games.
Origin of the project Arm at Valve
The initiative began between 2016 and 2017, when the company identified that Arm chips would dominate low-power devices. At the time, Valve recruited specialized open-source developers and financed the creation of Fex, an emulator capable of translating x86 code to Arm in real time.
Ryan Houdek, leader of the Fex project, confirmed that Valve has covered the costs that have allowed it to work exclusively on the emulator since 2018. The financing also covers continuous improvements to Proton, a fork of Wine optimized for games.
How running x86 games on Arm works
The process combines several layers of software. Proton translates API calls from Windows to Linux, while Fex translates x86 instructions to native Arm code only when necessary.
- The original game remains unchanged
- Only the game code is emulated; graphics libraries run natively
- Performance is greater than in traditional emulators because translation only occurs in critical sections
According to Griffais, the emulation stops when the game makes DirectX or Vulkan calls, which already execute in Arm code native to Proton.
Single SteamOS for all formats
There is no separate version of SteamOS for Arm. The operating system maintains the same Arch Linux base used in the Steam Deck and the future Steam Machine.
The difference is in the Proton package specific to Arm, which automatically includes Fex when it detects x86 code. Atualizações arrive simultaneously for all supported architectures.
Practical application on current smartphones
Users can now run games like Hollow Knight: Silksong on Samsung Galaxy S25 devices without an official version for Android. The procedure uses applications such as GameHub and the publicly available Proton + Fex layers.
Valve did not confirm plans to launch a “Steam Phone”, but Griffais stated that the company does not rule out any future possibilities.
Partnerships with hardware manufacturers
The company adopts an open stance towards collaboration with OEMs. Já there were contacts with manufacturers of living room consoles, handhelds and possible Arm notebooks.
The initial focus remains on delivering the Steam Machine and Steam Frame, but the executive highlighted that support for new Arm devices will be gradually expanded through SteamOS updates.
Future of gaming devices
Griffais predicts growth in handhelds below the Steam Deck performance level using Arm chips. Ele also mentioned potential for ultraportable laptops and even desktops based on powerful SoCs similar to those of the Apple.
Valve maintains the philosophy of investing in open technologies that benefit the entire PC ecosystem, preventing developers from wasting time on specific architecture ports.