Windows 10 on ARM to Support 64-Bit x86 Apps

Windows 10 on ARM still has far too many limitations to recommend, but one of the most serious may soon be eliminated. According to a recent code commit on GitHub, Microsoft is preparing to add support for 64-bit x86 application emulation to the platform.

“Add linker support for x64 code emulation on ARM64,” is literally all the code commit says. It was posted by Microsoft’s Kenny Kerr, a principal software engineer on the Windows team.

As you may know, Windows 10 on ARM is now a 64-bit ARM platform—it was 32-bit originally—but it can currently run 32-bit x86 software code in emulation. This change would dramatically expand this capability to include 64-bit x86 software—or what some call x64 software—-making the platform a lot more viable.

And Windows 10 on ARM has always had lots of problems and has been, to date, mostly an experiment and, for users, an exercise in frustration since so much does not work properly. The performance has been terrible. The compatibility issues are rampant, not just 64-bit x86 apps but all x86 drivers.

Microsoft and Qualcomm have addressed some of the performance issues by improving the chipsets used to power Windows 10 on ARM devices. But the software issues remain a challenge, and I don’t believe that adding 64-bit x86 app support, while very useful, will solve that drivers problem.

But still, it will be a step forward. Microsoft had always planned to add support for 64-bit x86 apps, as I wrote back in February 2018. But this commit seems to indicate that that support could arrive as early as this year.

Whether it puts Windows 10 on ARM over the top is unclear: Intel- and AMD-based PCs already provide 100 percent compatibility with x86/x64 software and drivers, and many modern PCs provide the battery life benefits that Microsoft champions on ARM. So it’s not clear what Microsoft and Qualcomm can do to put Windows 10 on ARM over the top.

Still, this is a big news and an important step forward.