Proton 11.0 Beta: launching Windows games on ARM via Steam

Proton 11.0 Beta 1: ARM Support and Boost for Multithreaded Games

Valve has released the first beta version of Proton 11.0, based on Wine 11.0, with a key new feature—native support for the ARM64EC architecture. This enables running Windows games on ARM devices through Steam without third-party emulators, including experimental builds on platforms like the Nintendo Switch.

Architectural Breakthrough: ARM64EC and FEX

The main change in Proton 11.0 Beta 1 is the integration of the FEX emulator version 2604 with ARM64EC (ARM64 Exception Handling Compatibility) support. This technology allows x86/x86_64 applications to run on ARM processors without manual compatibility tweaks. Previously, users had to rely on third-party solutions or manually modify their systems. Now everything works out of the box via Steam Play.

Enthusiasts have already tested the build on the Nintendo Switch, running the Steam client alongside the Steam Runtime environment for ARM and the compatibilitytools.d folder. This paves the way for expanding the Linux gaming ecosystem to mobile and hybrid devices.

Performance Optimization and Synchronization

Proton 11.0 includes a new thread synchronization mechanism called NTSYNC, designed to improve efficiency in multithreaded applications. It replaces outdated esync and fsync in various scenarios and provides more accurate matching of Windows kernel behavior.

FEX-2604 incorporates the following optimizations:

• Dynamic first-level cache activates only when needed;
• Second-level cache is disabled by default;
• JIT processing of trigonometric operations with reduced precision is accelerated by 3.7 times.

These changes are especially noticeable in games that heavily use math computations and multithreading, such as Bayonetta and Fallout: New Vegas. On systems with 8–16 GB RAM, memory savings amount to several hundred megabytes.

Expanded Game Support

The list of officially supported games in Proton 11.0 Beta 1 has grown significantly. Among the new titles:

• Universe Generator: The Golden Sword
• DCS World Steam Edition
• Resident Evil (1996) and Resident Evil 2 (1998)
• Dino Crisis and Dino Crisis 2
• From Dust
• Blaite
• Don't Die Dateless, Dummy!
• METAL GEAR SURVIVE
• Warhammer: Vermintide 2
• Metal Fatigue
• SHOGUN: Total War
• Unknown Faces
• Gothic 1 Classic
• X-Plane 12
• Breath of Fire IV
• Deadly Premonition

This means Valve has tested these projects and confirmed their stable performance through Proton without additional user tweaks.

How to Enable Proton 11.0 Beta

To use the new version, you need to:

• Open the game's properties in the Steam client;
• Go to the "Compatibility" tab;
• Enable the "Force the use of a specific Steam Play compatibility tool" option;
• Select "Proton 11.0 (Beta)" from the list.

On first launch, the client will automatically download the necessary components. For global default application, go to Steam settings → Compatibility and select the desired build.

Key Highlights

• ARM64EC support allows running x86/x86_64 games on ARM devices without external emulators.
• NTSYNC boosts multithreaded game performance through more accurate Windows synchronization emulation.
• FEX optimizations reduce memory usage and speed up math operations.
• Expanded supported games list includes both classics and modern titles.
• Steam Play activation remains simple and requires no manual system intervention.

— Editorial Team