Steam Deck

With a big dev like valve backing it they could probably implement a pretty impressive JIT/cacheing scheme - of course nothing beats native but this gap will close over time

Well, not exactly... WINE is a compatibility layer for syscalls between the x86 Windows API and (among others) the x86 Linux API, quite similar to how DXVK translates from DirectX to Vulkan.

What proton does is combine utilities like Wine and DXVK into a user friendly bundle, along with contributing substantially to the projects it bundles to make them interoperate well.

This looks to me like they want to bundle another utility, which does fast emulation of x86 user code on an ARM Linux system. Another commentator mentioned they are using FEX for this, which looks to me to do the same core task as qemu-user, but more focused on x86 to ARM and generally user-friendlier. That emulator could then be used to run x86 Wine on ARM.

The way qemu-user and FEX emulate one ISA on another is actually very cool btw. They realise massive speed gains by intercepting syscalls and executing them directly, instead of emulating a whole x86 Linux system.

I'd assume "FEX" in the last tweet in the OP is referring to this: https://github.com/FEX-Emu/FEX

I could see a budget Deck with an ARM processor, but I still doubt the flagship model wouldn’t be x86-64

In the shorter-term the issue is the lack of sufficiently powerful commercially-available RISC-V hardware for the level of gaming people expect out of a Steam Deck or VR headset, which ARM already has a number of SOCs capable of.

I don't doubt that the work will continue but Valve isn't likely to pour time or money into it until they think the hardware is there.

Steam for Android ready to play my PC games from my phone sounds awesome, not gonna lie.

Largest addressable market for Proton on ARM is Apple M-series devices.

Intel claims to have caught up with the upcoming Lunar Lake series but still to be seen.

That may be too late for whatever new device Valve is working on as given the lead time for such devices they may already have committed to an architecture for devices next year.

Also running X86 games on Arm devices is not likely to be efficient. I doubt the energy efficiency of Arm chips would outweigh the overhead of X86 to Arm translation?

But it's all speculation - even without hardware, getting Proton to work with Arm is good for steam regardless of any specific devices. For example it would allow steam to push the compatability tools onto Mac devices and even potentially mobile devices. Makes sense for Valve to do this without it meaning anything more that it being a god idea in itself.

Part of how they're identifying that proton arm and steam Waydroid exists is that the tools are being used to test VR games uploaded to steam, or were uploaded in a batch of other VR assets.

I fully hope to see this apply to Steam Deck/Chromebooks/Android/etc, but right now any hints of these have been VR specific. We haven't seen the Proton ARM before, but previous leaks about Waydroid have also all been VR related.

is there any ARM chipset out there that can deliver performance on par with the Steam Deck’s CPU

Yes, but they're made by Apple.

Winlator already does this on Android, for what it's worth. Oblivion plays fine on my phone although touch input sucks.

As for games on Asahi, there's box64/box86 to accelerate games (redirecting graphics APIs and such to native code).

You can already run apps made for foreign architectures by simply installing the right qemu package (not the virtual machine, the binary translator) and running the software using standard Wine. Conversely, you can also run Raspberry Pi software this way on normal PCs, which has proven very useful to me for cross compilation scenarios.

I assume Valve will take all of this tech and optimise it a bit more. If you're on a MacBook, your biggest challenge will probably be driver support, which is advancing at a rapid pace, but I'm not sure if you can get maximum performance out of it yet.