By Valve revealed this week it’s been secretly funding ARM gaming technology for nine years. Pierre-Loup Griffais, the company’s Steam Deck designer, told The Verge on December 2 that Valve has been bankrolling the FEX emulator project since 2016—a decade-long stealth operation to make Windows games run on ARM processors. The goal? Let your entire Steam library work on phones, tablets, and ultraportables without developers lifting a finger.
Why Stay Quiet for Nine Years?
Most tech companies announce vaporware and ship nothing. Valve did the opposite: they built FEX for nearly a decade before telling anyone. “We knew there was close to a decade of work needed before it would be robust enough people could rely on it,” Griffais explained. Ryan Houdek, FEX’s lead developer, confirmed Valve has funded him full-time since landing the project’s first commit in November 2018.
However, this isn’t hype-driven marketing. Valve needed production-ready technology before announcing anything. Unlike Proton, which built on the existing Wine project, FEX required ground-up development. The Hacker News community noticed—the reveal hit 584 points with 522 comments, signaling massive developer interest.
How Proton + FEX ARM Gaming Works
Valve’s ARM solution combines two translation layers. Proton handles Windows API calls, translating DirectX to Vulkan like it does for Steam Deck. FEX sits underneath, translating x86 instructions to ARM on the fly. Furthermore, here’s the clever part: when your game makes graphics API calls, execution switches to native ARM code. No emulation overhead for system-level operations.
Performance keeps improving. Cyberpunk 2077 saw a 38.9% speed boost in the FEX 2508 release alone, mostly from call-return stack optimizations that leverage ARM CPUs’ own prediction hardware. The FEX emulator supports modern x86 extensions including AVX and AVX2, with an experimental code cache to minimize stuttering. Monthly releases bring continuous gains.
The overhead is real but manageable. Apple’s Rosetta II shows similar games lose 30-50% performance through translation, though native ARM titles run beautifully. FEX’s numbers suggest it’s competitive with or better than Apple’s approach, and it’s improving faster.
Steam Frame VR: First ARM Gaming Hardware Proof
The reveal makes sense now: Valve’s Steam Frame VR headset, announced in November, uses Qualcomm’s Snapdragon 8 Gen 3 ARM chipset. Consequently, it’s the first SteamOS device abandoning x86 architecture—Steam Deck runs Intel-compatible chips. FEX is why this works at all.
Steam Frame launches early 2026 with 2160×2160 per eye displays, 16GB of RAM, and refresh rates up to 144Hz. Moreover, Valve calls it “streaming-first,” bundling a wireless PC dongle for heavy games. The ARM chip handles lighter titles locally while tapping your gaming PC’s horsepower for demanding ones. It can even run Android APKs natively.
Griffais hinted at more: “I think that paves the way for a bunch of different, maybe ultraportables, maybe more powerful laptops being ARM-based.” Translation: this is just the beginning. Valve spent nine years preparing for a post-x86 portable gaming world.
Will ARM Gaming Actually Work?
The debate is performance. x86 still dominates gaming PCs, and for good reason—games are optimized for that architecture. Nevertheless, ARM wins on battery life and enables thinner devices, but translation layers cost performance. Apple proved ARM gaming can work, but only when the software is good enough.
FEX’s ongoing improvements suggest Valve is serious about matching or exceeding Apple’s Rosetta II. The difference? FEX is open source. Developers can contribute, and any ARM Linux device can use it. Valve’s philosophy: “We don’t want game developers to have to spend a bunch of time porting things to different architecture if they can avoid it.”
This isn’t about ARM replacing x86 for gaming desktops. It’s about enabling new form factors that couldn’t exist before. VR headsets need ARM for weight and battery constraints. Additionally, ultraportables benefit from ARM’s efficiency. Phones and tablets already run ARM exclusively.
Gaming Anywhere: Vision vs Reality
Developers are already testing Steam games on Samsung Galaxy phones through the GameHub app, which uses Valve’s FEX stack. Games like Hollow Knight: Silksong run on mobile hardware. It’s rough—NotebookCheck’s review bluntly advised “avoid it unless your tolerance for frustration is high”—but the concept is proven.
Valve’s timeline is realistic. Steam Frame’s 2026 launch proves the technology is production-ready for dedicated hardware. Smartphone gaming through FEX will take longer to mature. Think five to ten years for a smooth experience across billions of ARM devices, not next quarter.
The stealth strategy paid off. Valve built robust technology before announcing anything, ensuring developers wouldn’t waste time porting games. FEX’s open-source nature benefits the entire PC gaming ecosystem, not just Valve’s hardware. ARM gaming is coming, and Valve quietly spent nine years making sure it would actually work.
