Why x64 emulation on ARM matters

Generally, the processors in the computers around us are based on the x86 architecture. All AMD and Intel CPUs are x86 and that’s why most commercial/industrial-level professional applications, such as the Adobe Suite, are made to run on only 64-bit x86 CPUs. ARM, on the other hand, is an entirely different architecture and while it can run native 64-bit apps that have been coded for ARM, it can’t do the same for x86. Therefore, 64-bit x86 apps run in only 32-bit on ARM-based devices via emulation. Now, some apps like Google Chrome can go by fine with running as a 32-bit program, many others, more demanding apps simply can’t. They require a 64-bit x86 processor to even start. So, the only solution to this is emulation of 64-bit x86 on ARM processors so that the app is fooled that it’s running inside a 64-bit x86 environment. This emulation layer would cause a noticeable performance hit but it’s better than nothing. Now, you would at least be able to run 64-bit x86 apps on ARM-based Windows 10 machines. Not only that, but some 32-bit apps would also see an improvement in performance due to better memory utilization. So, ultimately this was a win-win in the end for everybody. It felt like Microsoft and Qualcomm were hard at work to make the x64 emulation layer as good as possible, and for a while everything was going smoothly. That was until today.

The Dread

The original blog post that announced the news of x64 emulation for Windows 10 on ARM in October 2020 now has a small update at the very start reading: Out of nowhere, Microsoft has gone on a limb and essentially axed the x64 emulation dream for Windows 10 on ARM. The actual program itself still lives on and Windows 10 on ARM will be supported till 2025 and 32-bit emulation of x86 will still work. But, the 64-bit (x64) emulation layer will stop receiving any updates going forward for Windows 10 on ARM.

Windows 11 on ARM

Microsoft has given no explicit reason for this decision and the announcement itself came out of the blue. The company did mention in their blog post update that Windows 11 is the place to be if you want to see and further test the future of 64-bit x86 emulation on ARM. Windows 11 on ARM has general support for x64 Intel app emulation and going forward, that’s where the developments will take place while x64 emulation for Windows 10 on ARM is dead. It’s clear that Microsoft aims to incentivize people to move to Windows 11 with this decision and considering the company’s main focus lies there at the moment, it’s not an unreasonable ask. However, this is a punch in the face for users who were eager and hopeful to see proper x64 emulation on Windows 10 on ARM. In a separate statement to Thurrott, a spokesperson from Microsoft had to say this:

Microsoft Kills x64 Emulation on ARM based Windows 10 PCs and Makes It Exclusive to Windows 11 Only - 6