Microsoft releases ARM64EC 17.3: Windows 11 on ARM ushers in full support

Back in June 2021, Microsoft announced ARM64EC for Windows 11. Officially, it was called a new way to get near-native performance from existing x64 applications on ARM platforms -- even if you called plug-ins and dependencies that didn't yet support that footprint. Now, a year later, ARM64EC is finally getting more complete support for Windows 11.

(Via : C++ Team Blogs)

The "EC" of ARM64EC is said to stand for "Emulation Compatible".

The idea is to provide a binary interface (ABI) so that developers can build applications using both x64 and ARM code.

This means that ARM code will run natively on Windows 11 devices, while other x64-specific code will run via emulation.

(Via Windows Blogs)

As a major milestone of the Windows on ARM project, the differences between the ARM64EC ABI and the ARM64 ABI are mainly in the following areas.

The ARN64EC ABI is binary compatible with x64 code and follows established x64 software conventions.

These include calling convention, stack usage, and data alignment.

This makes ARM64EC and x64 code interoperable, and applications built on the former may contain x64 code, but not always.

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This is because ARM64EC itself has a complete, first-class Windows Binary Interface (Windows ABI).

After more than a year of development, Microsoft now believes the ABI is stable enough to transition from the experimental phase to a general release (GA).

With the release of ARM64EC version 17.3, there are a number of benefits for developers.

For example, developers can gradually update their code to run both x64 and ARM functionality without the hassle of ensuring that their entire code base is ARM platform compatible.

Of course, on Windows on ARM devices, the performance of native ARM code is still slightly better.

Microsoft's idea, however, is to improve ARM performance through continuous codebase updates, but without losing any features in the process.