Valve is likely up to something with the hardware again, according to NotebookCheck. After the Valve Index, Steam Deck, and Steam Deck OLED, the next big hunk of plastic and wires could replace the x86 architecture favored by PC gamers with ARM, the processor type favored by the Nintendo Switch, Macs, and mobile phones.
SteamDB is revealing a piece of software called 'ValveTestApp3043620' that has been linked to dozens of PC games, from Left 4 Dead 2 and Garry's Mod to Among Us and Hollow Knight, and the games are tagged 'proton-arm64ec' and 'proton-arm64ec-experimental.' According to Occam's Razor, the mysterious app suggests that Valve is testing a version of Proton (the compatibility layer that allows Windows games to run on Linux-based SteamOS) that can run on ARM64 processors.
The most boring outcome of this would be Valve releasing SteamOS for MacBooks, with Apple’s M-series of mega-fast laptop and desktop chips arguably the most famous examples of the ARM architecture in action. But it’s equally likely that Valve will stick with x86 for its Steam Deck family and consider ARM as the basis for its next major hardware release.
I don't think the story here is the possibility of new Steam-branded kit – Valve has been in the hardware game for over a decade, since the first Steam Machines, and has given no signs of letting up. But the potential move to ARM could open up some new possibilities, albeit with some risks.
For one, ARM chips are typically more power-efficient than their closest x86 counterparts, so they could be a great fit as the foundation for a new Steam Deck or wireless VR headset. ARM’s compatibility with Android OS could make it much easier to add your favorite mobile games to your PC library; outside of emulation, this is only possible in very narrow, limited ways on x86 hardware.
However, the big challenge—for Valve and Proton—will be maintaining performance and compatibility. While modern ARM chips are no less powerful than x86 chips, the fact that most PC games are built solely for the latter can cause issues keeping frame rates up. That’s not a huge deal if Proton tricks Windows games into running on SteamOS, since both platforms were built with x86 in mind, but enabling those games on the completely different ARM64 architecture would likely involve something akin to full emulation, which would generally slow down performance.
Still, the whole point of the Proton is to beat the compatibility barriers to the punch, so who knows. And as for the hardware itself, I’m not convinced this will be an ARM-powered Steam Deck, partly because Valve told me last November that a next-gen Deck was probably years away. A standalone VR headset is a good bet, but given that ARM is forcing its way into Mac Pros, the efficiency benefits don’t necessarily translate to just portable use. A next-gen Steam Machine, perhaps? Watch this space.