64-bit app emulation enters public preview on Windows 10 on ARM

Surface Pro X
Surface Pro X (Image credit: Daniel Rubino/Windows Central)

What you need to know

  • Windows 10 on ARM is getting an updated emulator with 64-bit app support.
  • It's entering public preview today with build 21277.
  • ARM PCs can download it now via the Insider Dev Channel.

Microsoft has today announced the first preview build of Windows 10 on ARM to support 64-bit app emulation in addition to the x86 emulation layer already available. The updated app emulation later will allow Windows 10 devices powered by an ARM processor to run 64-bit apps that were compiled for Intel and AMD processors, meaning more apps can now run on Windows 10 on ARM as a result.

Previously, Windows 10 on ARM PCs were limited to ARM32, ARM64, and x86 compiled applications. This meant that any Windows app that was compiled for 64-bit Windows only wasn't able to run on Windows 10 on ARM. With the new emulation layer going into preview today, 64-bit Windows apps will now run on Windows 10 on ARM devices, albeit with lesser performance as the OS is emulating those apps, and not translating them on the fly like macOS does.

Microsoft is still recommending app developers compile their apps natively for Windows 10 on ARM as that will provide users with the best experience when it comes to app performance. But for those app developers who won't or can't, Windows 10 on ARM devices will no longer be left without.

Hari Palupaka, Partner Group Program Manager for Windows said the following:

While developers increasingly support ARM64 apps natively, emulating x64 apps is an important additional step in our journey with Windows 10 on ARM. Through working with Qualcomm Technologies, Windows on ARM PCs continue to deliver incredible battery life, connectivity capabilities with 4G LTE and 5G, and immersive experiences with AI acceleration and pen and touch capabilities – all essential as we are working, learning, and connecting from home and other remote locations.

Microsoft says that apps that have been running under x86 emulation, but have 64-bit compiles available, will benefit from the additional memory that 64-bit apps can take advantage of. This should mean some 64-bit apps that run in emulation perform better than x86 apps, but we'll have to test this ourselves to see if that's reflected in real world tests.

The new emulator is in preview right now, so there will likely be bugs and issues along the way. The first build to include 64-bit emulation is 21277 and is available now for Insiders in the Dev Channel on devices powered by an ARM processor.

Zac Bowden
Senior Editor

Zac Bowden is a Senior Editor at Windows Central. Bringing you exclusive coverage into the world of Windows 10 on PCs, tablets, phones, and more. Also an avid collector of rare Microsoft prototype devices! Keep in touch on Twitter: @zacbowden.

  • Excellent news for Pro X and WoA owners. Hopefully this exits beta soon.
  • Excellent? They're about to face the reality that their $999 (without keyboard, mouse or pen) investment is a "pro" wallpaper viewer. What's excellent about that?
  • Umm what but are you pulling this out of?
  • How about go trolling elsewhere?
  • Did you write this waiting in line for your M1 MacBook? You know, you can run Facebook on your phone too.
  • What about heat, fanless and battery life ?
  • The truth is that whatever advantages ARM has over X64 diminishes through emulation. A full transition of applications to ARM in Windows is almost impossible. and will take a very long time. What we need until then is more innovation from Intel and AMD. Their processors are pretty good but they need to be better at battery and connectivity..and there is no reason for ARM in PCs
  • Think of games and enterprise apps: Windows on ARM now has a full library of x86 and x64 programs, stuff which was never available on Intel MacOS in the first place. Chicken and egg issue. Newer apps can use UWP with full ARM compatibility or developers can rebuild older apps for ARM64. In the meantime, x86 and x64 compatibility means users aren't left out.
  • @zac Do we know when this hits at least the Release Preview? I had the Dev Release on my SPX but it was too unstable so I rolled back. Today I installed an X64 app that sadly doesn't work. I figured x64 emulation had been fully released by now but was mistaken.