Valve has been testing Arm64 support for Proton, but I wouldn't be too excited about a Steam Deck 2 based on Arm just yet.

Users with keen eyes have noticed a test application in SteamDB, which suggests that Valve is testing Arm64 support for Proton. This software allows Windows games to be run on Linux systems.

The changelog for ValveTestApp3043620 lists several popular games--including Left 4 Dead 2, Garry's Mod, Kerbal Space Program and more--with added tags like "proton-arm64", "proton-arm64e" and "protonarm64ec-vanguard" (via Notebookcheck).

This has led some to speculate that Valve is preparing to support certain games via Proton for Arm64 devices such as Android smartphones and tablets or even a version of Valve’s ever-popular Steam Deck based on Arm64.

While the idea of Steam games running directly on your phone (and an Arm based Steam Deck is a strange thought), it's more likely that this is a test for Windows support on Arm based chips.

In recent months, the Arm architecture has made waves with the announcement of several laptops that feature Qualcomm's Arm64 based Snapdragon X processors. These new mobile devices can run Windows-based games through a Microsoft/Qualcomm emulator layer called Prism.

If Proton could provide Windows-based emulators for games, it would be a direct competitor of Prism. And if it was able provide better performance or a more stable emulation, it would be incredibly beneficial for gamers who are looking to adopt Arm devices.

Another possible use would be a rumoured Arm VR headset that could run both Android and Windows-based games. Valve appears to be at least experimenting with Arm64 emulation with Proton, regardless of the end use.

Who knows what it will look like? I'm still sceptical about any rumours of an Arm-based Steam Deck being released soon. Next-gen Decks will be based on power efficiency. While Snapdragon chips aren’t bad, Valve is likely to wait a while to see what future chips can do.

We're not expecting a Lunar Lake shock. That would be amazing, wouldn't it? See, I'm a good speculator, too.