At first, watchOS 26 looks like a small upgrade. Unlike iOS, iPadOS, and macOS, which feature a complete revamp of their UI, the Apple Watch update is definitely more subtle. However, as spotted by MacRumors, Apple rebuilt its watchOS software to transition some of the newest Apple Watch models to full ARM64.

In Apple’s watchOS 26 video for developers, the company explains that the Apple Watch Series 9, Apple Watch Series 10, and Apple Watch Ultra 2 are moving from arm64_32 to the full arm64 architecture.

As explained by MacRumors: “The standard arm64 architecture provides 64-bit pointers and access to broader memory ranges, enhanced performance, and increased compatibility with general-purpose ARM computing standards. The move also opens the door for potentially more complex and computationally intensive watchOS applications, since arm64 provides access to more registers and system resources compared to the more compact arm64_32.”