What you need to know
- A preview build of Windows 11 improves Prism emulation for apps.
- The “major feature update” adds support for more CPU features under emulation, including using AVX and AVX2, BMI, FMA, and F16C extensions.
- Adobe Premiere Pro 25 already uses some of the new Prism emulation features to run on Windows on Arm PCs.
Windows on Arm PCs powered by chips like the Snapdragon X Elite processor are about to get a nice boost. Microsoft is testing an update to its Prism emulation software that adds support for running more CPU features under emulation. The change will help non-native Arm applications run better on the best Copilot+ PCs.
The new feature is in testing among Windows Insiders in the Canary Channel. Microsoft rolled out Build 27744 to the channel recently. Interestingly, support for additional extensions is not entirely new. Adobe Premiere Pro 25 already uses some of the newly supported extensions when run through Prism emulation. But starting with Build 27744, any x64 app under emulation will have access to the expanded list of extensions.
Diving a bit into the nitty gritty, apps running through Prism emulation now have support for more extensions, including AVX and AVX2, BMI, FMA, and F16C. Windows does not require those extensions to run, but many apps rely on them.
The new CPU features are limited to x64 applications running through Prism emulation. Below, I’ve reshared the full change log in Build 27744 shared by Microsoft.
Assuming all goes well during testing, the improvement to Prism emulation should make its way to all PCs that utilize the feature in the near future. The list of the best native Windows on Arm apps grows regularly, but there are still plenty of apps that need to run through emulation.
What’s new with Build 27744
New Processor Feature Support in Prism
In today’s Canary Channel Insider Preview build, we’re previewing a major feature update to Prism, our emulator for Windows on Arm, that will make it possible for more 64-bit x86 (x64) applications to run under emulation by adding support for more CPU features under emulation.
This new support in Prism is already in limited use today in the retail version of Windows 11, version 24H2, where it enables the ability to run Adobe Premiere Pro 25 on Arm. Starting with Build 27744, the support is being opened to any x64 application under emulation. You may find some games or creative apps that were blocked due to CPU requirements before will be able to run using Prism on this build of Windows.
At a technical level, the virtual CPU used by x64 emulated applications through Prism will now have support for additional extensions to the x86 instruction set architecture. These extensions include AVX and AVX2, as well as BMI, FMA, F16C, and others, that are not required to run Windows but have become sufficiently commonplace that some apps expect them to be present. You can see some of the new features in the output of a tool like Coreinfo64.exe.
Note that in today’s preview, only x64 applications can use these new CPU features. If you have a 32-bit app or a 64-bit app that uses a 32-bit helper to detect CPU feature support, that app won’t detect the new features in Prism.
We welcome any feedback from Insiders who are interested in trying out apps and games using this early preview of Prism. Please submit any feedback on compatibility issues or performance regressions through the Feedback Hub (Win + F) under Apps and the specific app you’re seeing issues with (if you don’t see the app listed, use “All other apps”) to help us to ensure that this updated Prism provides a great experience.
Thanks for helping us improve emulation on Windows. We’re excited to see customers able to run more apps and games that they care about on Windows on Arm!
Changes and Improvements
- “All apps” is now just “All” on the Start menu.
Input
- We’re beginning to roll out a new Gamepad keyboard layout for the on-screen keyboard in Windows 11 that supports the ability to use your Xbox controller to navigate and type. This includes button accelerators (example: X button for backspace, Y button for spacebar) additionally the keyboard keys have been vertically aligned for better controller navigation patterns.
Task Manager
- We’ve updated the design of the Disconnect and Logoff dialogs in Task Manager to now support dark mode and text scaling.
- In the Performance section we now label listed disks with their type.
Settings
- The detach virtual hard disk (VHD/VHDx) button we added under Settings > System > Storage > Disks & Volumes introduced with Build 27686 is now back with this build after being temporarily disabled starting with Build 27718.
