What Is Prism? Windows 11 x86 Emulation on Arm, Explained

Most Windows software is compiled for x86/x64 processors. Arm PCs — like laptops built on Snapdragon X chips — use a different instruction set, so they can’t run that code directly. Prism is the emulation layer built into Windows 11 on Arm that bridges the gap: it translates x86 and x64 instructions to Arm64 on the fly, letting most existing Windows apps run without any changes.

How Prism works

When you launch an x64 app on an Arm PC, Prism translates blocks of its machine code into Arm64 instructions and caches the result, so frequently used code paths only pay the translation cost once. After the first launch, apps typically start faster and run smoother because much of the translation is already cached on disk.

Prism supports both 32-bit (x86) and 64-bit (x64) applications. A 2025 Prism update (after the initial 24H2 release) also began exposing more modern CPU features to emulated apps — including the AVX and AVX2 instructions that some games and creative tools require.

What performance to expect

Emulation adds overhead, but for everyday software it’s smaller than most people assume. Office suites, chat clients, password managers and most utilities feel close to native. The gap widens for compute-heavy work — sustained video encoding, large compiles, scientific workloads — where a native Arm64 build can be dramatically faster and far more battery-efficient. See Native Arm64 vs Emulated for a deeper comparison.

What Prism can’t do

Emulation covers applications, not low-level system code. The common blockers:

• Kernel drivers — x64 drivers can’t be emulated. VPN clients, antivirus engines and copy-protection drivers need Arm64-native versions.
• Kernel-level anti-cheat — many competitive multiplayer games refuse to run for this reason (details in our Snapdragon gaming guide).
• Shell extensions and plugins that inject into native processes must match the host architecture.

How to tell if an app is emulated

Open Task Manager → Details tab → add the Architecture column. Emulated apps show x64 or x86; native ones show ARM64. Our step-by-step guide: How to check an app’s architecture.

Check before you assume

Compatibility is per-app, and it changes monthly as vendors ship Arm64 builds. Search our database of 8,000+ verified titles to see whether a specific app runs natively or under emulation.