For over a decade, Steam company Valve’s biggest goal has been bringing Windows games to Linux. While that goal is almost complete with the massive success of Proton compatibility on Steam Deck and the upcoming Steam Machine, the company has also been secretly pushing to bring Windows games to ARM devices. 

In an interview with The Verge, Steam Deck and SteamOS lead Pierre-Loup Griffais revealed that Valve has been secretly funding Fex, an open-source project to bring Windows games to ARM, for almost a decade. 

“In 2016, 2017, there was always an idea we would end up wanting to do that,” the SteamOS lead said, and that’s when the Fex compatibility layer was started, because we knew there was close to a decade of work needed before it would be robust enough people could rely on it for their libraries. There’s a lot of work that went into that.”

Griffais explained that the project pushes to “reduce barriers for users not having to worry about what games run”. With Windows games running on ARM, a large number of Steam games are able to run on a significant number of additional devices including low-power laptops, tablets and even phones (hopefully) without issue. 

While Griffais didn’t confirm specific devices that Valve is working on, the SteamOS lead explained that they’re “excited” about creating potential ARM-based devices. “I think that it paves the way for a bunch of different, maybe ultraportables, maybe more powerful laptops being ARM-based and using different offerings in that segment,” he said. “Handhelds, there’s a lot of potential for ARM, of course, and one might see desktop chips as well at some point in the ARM world.”

But why ARM? The Steam Deck lead explained that the hardware offers more efficiency at lower power compared to other options. While the current hardware in the Steam Deck and other handhelds can run at low-wattage, they’re simply less efficient at lower-power than hardware designed specifically to run at that spec. 

“There’s a lot of price points and power consumption points where Arm-based chipsets are doing a better job of serving the market,” they said.  “When you get into lower power, anything lower than Steam Deck, I think you’ll find that there’s an ARM chip that maybe is competitive with x86 offerings in that segment.”

“We’re pretty excited to be able to expand PC gaming to include all those options instead of being arbitrarily restricted to a subset of the market,” they continued. 

Valve is currently working on an ARM version of SteamOS using “the same exact OS components, the same exact Arch Linux base, all the same updater, all the same technologies,” Griffais said. 

“When  you’re looking at SteamOS on Arm, you’re really looking at the same thing,” he continued. “Instead of downloading the normal Proton that’s built for x86 and targets x86 games, it will also be able to download a Proton that’s Arm-aware, that has a bulk of its code compiled for Arm and can also include the Fex emulator.”

All of this is to give players a choice. While Windows games are built for Windows, they don’t necessarily need to be played on Windows. Valve has already proven how effective this can be with some games Windows running via Proton performing better due to the lack of Windows bloat.