x64 Emulation Coming to Windows 10 on Arm Platforms

Microsoft this week announced that it would finally enable x86-64 (x64) emulation on its Windows 10 on Arm operating system in November. The move will further blur the line between Arm and x86 processors at least as far as Windows 10 is concerned, but it remains to be seen how well the emulation works this time. 

The software giant will first enable x64 emulation for Windows 10 on Arm PCs for members of its Windows Insider Program this November. The emulation will work on all Windows 10 on Arm systems released in the last couple of years no matter which application processor they use. It is unclear when Microsoft intends to make x86 emulation for Armv8 SoCs generally available, but it probably should not take too long time for the firm to test it with various programs to ensure that it works without major problems. 

Also, the company intends to introduce a revamped version of its Edge browser that works faster on 64-bit Arm SoCs and consumes less power. In addition to letting end-users run x64 apps on their Windows 10 on Arm notebooks, Microsoft will also release several of its programs, including Microsoft Teams and Visual Studio, optimized specifically for Arm SoCs. Last but not least, Microsoft is also expanding its App Assure program to include Windows 10 on Arm 64-bit devices to ensure that programs developed for specific customers would work on all Windows 10 platforms no matter which hardware they use. 

Microsoft has a long history with Arm and Windows in the PC space. Microsoft first announced plans to release a Windows operating system for 32-bit Armv7 SoCs back at CES 2011 to a large degree because it wanted to compete against Apple’s iPad. The software company launched its Windows RT in late 2012. The launch was supported by Microsoft’s own Surface tablet along with hybrid systems from ASUS, Dell, Lenovo, and Samsung.  

Windows RT came with typical apps pre-installed and Microsoft also released a version of Office optimized for Arm. But because Windows RT could not run traditional Windows applications and Armv7 SoCs at the time were not powerful enough to emulate x86 or x64, the platform has never captured a significant market share. Microsoft itself canned all of its own Windows RT devices in early 2015 after all of its hardware partners ceased to make their systems. 

Microsoft second attempt to bring together Windows and Arm was unveiled in 2017 together with Qualcomm. The main value proposition of Qualcomm-powered always-connected personal computers (ACPS) was an integrated modem as well as a long battery life.  

This time around, Microsoft and Qualcomm considered mistakes that were made earlier. Firstly, because modern Snapdragon SoCs offer considerably higher performance when compared to Armv7 application processors from early 2010s, Microsoft’s Windows 10 on Arm ACPCs perform much better when running software compiled for Armv8. Secondly, Microsoft now offers a special SDK tailored for Windows 10 on Arm. Thirdly, Windows 10 on Arm can run Win32 applications in emulation mode, though not without glitches. Finally, Qualcomm now offers SoCs specifically tailored for PCs. 

Bringing x64 emulation to Windows 10 on Arm machines will increase their compatibility with modern software, which will inevitably make them more attractive for end-users over time. As a result, competition between Arm and x86 will intensify in the PC space.