FEX: A fast usermode x86 and x86-64 emulator for ARM64 Linux

Run PC apps on ARM gadgets — fans cheer while skeptics ask “but why”

TLDR: FEX lets ARM64 Linux run PC apps and even games, with features to reduce stutter and boost performance. Comments hype possible Valve-backed work and demand proof it beats qemu/box64, while joking about the “curl | python” installer and asking the eternal question: can it run Doom?

ARM owners are buzzing: FEX promises to let your ARM64 Linux device run old-school PC apps — even Windows games via Wine/Proton — and the comments lit up. One superfan called the performance “incredible,” while another dropped a bombshell: claims that Valve funded Igalia to boost FEX for a Snapdragon-powered Steam headset, linking to Igalia’s post here. Cue the hype, the side-eyes, and the “is this the future of gaming?” speculation.

But drama arrived fast. A veteran chimed in with “HN déjà vu,” pointing out the last thread had 300 points and 137 comments — the crowd’s already split. The top beef? “FEX vs the rest.” Folks kept asking how it really differs from qemu-user or box64. Translation: the nerds want receipts, not vibes.

There were laughs too. The install command is “curl a script and pipe it to Python,” which triggered classic memes about “never pipe the internet into your machine,” followed immediately by “okay fine, I did.” Meanwhile, gamers joked about testing “Can it run Doom?” and “Elden Ring on a smart fridge” while devs drooled over FEX’s tricks: forwarding graphics to your system (OpenGL/Vulkan), an experimental cache to cut stutter, and per-app tweaks in the friendly FEXConfig. Big promise, bigger expectations — and peak comment-section energy.

Key Points

  • FEX is a usermode emulator enabling x86 and x86-64 applications to run on ARM64 Linux.
  • It can be used with Wine/Proton to play Windows games on ARM64 systems.
  • Performance features include API forwarding to OpenGL/Vulkan, an experimental code cache, and per-app configuration.
  • FEXConfig provides a GUI for tuning settings, including options like skipping memory model emulation.
  • FEX requires ARMv8.0+ hardware, an x86-64 RootFS (via FEXRootFSFetcher), and offers a PPA-based installer for Ubuntu; other distros use the FEX-Emu Wiki guide.

Hottest takes

"Valve/Steam have been funding Igalia to do some further work here on FEX, supporting Valve's Qualcomm Snapdragon 8 gen 3 powered Steam Frame headset" — jauntywundrkind
"300 points | 14 days ago | 137 comments" — jasonjmcghee
"Readme mentions 'similar to qemu-user and box64' but don't talk about differences so not sure why this would be better to use than that" — knowitnone3
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