> It supports forwarding API calls to host system libraries like OpenGL or Vulkan to reduce emulation overhead. An experimental code cache helps minimize in-game stuttering as much as possible. Furthermore, a per-app configuration system allows tweaking performance per game, e.g. by skipping costly memory model emulation. We also provide a user-friendly FEXConfig GUI to explore and change these settings.
> On the technical side, FEX features an advanced binary recompiler that supports all modern extensions of the x86(-64) instruction set, including AVX/AVX2. The heart of this recompiler is a custom IR that allows us to generate more optimized code than a traditional splatter JIT. A comprehensive system call translation layer takes care of differences between the emulated and host operating systems and implements even niche features like seccomp. A modular core enables FEX to be used as a WoW64/ARM64EC backend in Wine.
Used by the new Steam Frame (https://store.steampowered.com/sale/steamframe) which is an ARM64 Snapdragon 8 Gen 3 that will run PC and PCVR gaming titles.
I've tested it on an Ampere workstation, and was trying it on a Pi, but it seems with Trixie, there may be some bugs with both that and box64 right now, I was having trouble with both of them.
https://news.ycombinator.com/item?id=45903610#:~:text=Valve%...
The Alpha was such a great platform. It is too bad it’s reign was so brief.
FEX is the shootstring, extra special discount budget (not maligning) version of Rosetta. Apple should sell Rosetta to Valve.
The other stuff is all present in ARMv8.5 I think.
QEMU exists. I doubt they want the bad press of suing an Open Source project everyone is using.
Isn't Rosetta kinda bad though? And won't get much better because it's not open source?
Gabe Ownership/co-founder:
- Valve - Yacht Companies - Starfish Neuroscience (Neuralink) - Submarine Companies
https://interfacinglinux.com/2025/06/30/fex-emu-gaming-on-th...
The old games don't really matter with regards to FEX perf, so the only relevant bit is the semi newer games at 30/40 fps, which seems very slow to me, given that you are only running at 1080p/Medium, so you likely have a CPU bottleneck there.
FEX also has settings which weaken or disable TSO altogether, favoring performance over correctness. You wouldn't want to rely on those for anything important but a game possibly crashing isn't the end of the world.
The history of the PC is one of commoditization. A fractured multi-polar landscape is detrimental to the ecosystem/productivity and should ultimately fail.
x86 emulation is an important puzzle piece, and I'm happy Valve recognizes this and sponsors it.
Only the CPU code has to be emulated. The GPU runs natively.
That does not help with poorly supported GPUs of course.
A little old but still interesting.
Fex straight drm games.
(I know I'm describing an M2 Air, but I'd like to explore alternatives.)
As you can tell from my past comments about Chromebooks as Linux workstations here, I'm a daily user and very happy with them.
Qualcomm is already upstreaming support into Linux.
Qualcomm is already upstreaming support into Linux.
Take this with a grain of salt but since we are one the topic of games….
https://www.techpowerup.com/343081/qualcomm-says-90-of-games...
