Microsoft Begins Publicly Testing Windows 10 on ARM x64 Emulation

Posted on December 11, 2020 by Paul Thurrott in Windows 10 with 18 Comments

A newly-released Windows Insider Preview build is giving the public its first chance to experience x64 app emulation in Windows 10 on ARM.

“When we first launched Windows 10 on ARM in late 2017, the long tail of apps customers needed were [sic] dominated by 32-bit-only x86 applications, so we focused our efforts on building an x86 emulator that could run the broad ecosystem of Windows apps seamlessly and transparently,” Microsoft’s Hari Pulapaka explains, somewhat disingenuously. “Over time, the ecosystem has moved more toward 64-bit-only x64 apps and we’ve heard the feedback that customers would like to see those x64 apps running on ARM64. That’s why we are working on expanding the capability of our emulation to include x64 applications and sharing this first preview to gather feedback.”

In this first preview, which is part of Windows 10 Insider Preview build 21277, part of the Dev channel, those using Windows 10 on ARM can now install x64 (64-bit x86) apps from the Microsoft Store or from any other location of your choosing. These apps may benefit from having more memory when run as 64-bit emulated apps, Pulapaka says.

What everyone is wondering about, of course, is performance. Pulapaka only addresses that in passing—both compatibility and performance will “improve over time,” he says–but users are advised to install a preview version of the Qualcomm Adreno graphics driver for the best experience with this particular build. You can find download links here. You will also want to install a preview version of the ARM64 C++ redistributable.

I will be testing this new functionality as soon as possible.

Tagged with

Join the discussion!


Don't have a login but want to join the conversation? Become a Thurrott Premium or Basic User to participate

Comments (18)

18 responses to “Microsoft Begins Publicly Testing Windows 10 on ARM x64 Emulation”

  1. nbplopes

    Can’t just they test this thing internally considering the device is also of their doing / Surface X? How lame is that?

    • SvenJ

      In reply to nbplopes: They have all their people building it. They don't have time to test it too.

    • evox81

      In reply to nbplopes:

      I feel like what you're saying is just test it internally, with no external testing, and release it when it's ready. While I think Microsoft leans on their "insiders" a little too much, external testing is vital to software development. Testing a product within the sterile software/hardware confines of the company that made it will never be sufficient. You would never be able to test the types of scenarios that only happen in the real world. Hell, even in the real world, you won't be able to test every eventually... at least not until it arises.

      • nbplopes

        In reply to evox81:

        No. I’m not advocating not doing public beta tests. Is this a public beta test? What is this insider preview ring thing, public beta? Of course not!

        This ring thing is just tech marketing. Use public beta testing, a well known best practice, for 3 months or so and release it with bugs close to none if any ... if possible fast too. But I guess “it will improve over time” ... means ... “maybe in 4 years or so of tech marketing”.

  2. coachjonno

    And it is already running on Lumia 950xl

  3. princenegi

    Nokia PureBook X14 will soon

  4. jimchamplin

    When are they going to do the right thing and offer a Windows 10 package for RPi 4? Offer images for Home, Pro, and Enterprise, and make it easy to activate with an existing license.

    That would provide an immediate and very interested audience, give WoA another system to target, thus improving compatibility, as well as show Qualcomm that their foot-dragging isn’t a good thing.

    Maybe Microsoft should just design their own high performance ARM SOC and sell it to hardware partners. Qualcomm would get totally Apple’d!

    • Paul Thurrott

      We could only guess, but Microsoft officially supporting Pi PCs with mainstream Windows 10 is expensive from a support/maintenance perspective. There would have to be a sizable potential audience there. Also, I feel like the whole Pi thing is based around free software. Does it then make Windows 10 for Pi free? And how does that impact its other non-Pi partners? Etc. All that said, would love to see real Windows 10 on Pi.
  5. Scsekaran

    It seems like more people are upset that Microsoft provided x64 compatibility rather than upbeat about it

  6. crunchyfrog

    Windows on ARM is a great idea but years later it's still not close to being ready even though MS has launched hardware to use it. It's like taking a cruise on a ship that's not even sea worthy yet.

  7. steam960

    I would love to see it replace Android on the Surface Duo!

  8. SvenJ

    I just wish they would make that keyboard for regular Surfii Pro too. The pen storage is brilliant.

  9. redstar92

    XBOX app does not open :( WIll try nvidia geforce now next.

  10. bschnatt

    It'll be interesting to see how performant this is on systems with only 4GB of RAM, like my HP Envy x2 laptop. Disk space isn't a problem, but memory probably will be - can you say "paging file thrashing"? I hope Microsoft is porting Visual Studio to ARM; that would be a bigger deal for me...

  11. behindmyscreen

    Why can't they just say the reality? "32 bit was easier to emulate so we did it first"

  12. winbookxl2

    I can't wait to try it!