Apple is making a significant technical change in watchOS 26, transitioning the latest Apple Watch models to a more advanced architecture called full arm64. This isn’t just tech jargon; it’s a fundamental shift under the hood that could impact how your watch performs and what future apps can do. For owners of newer Apple Watches, this change lays the groundwork for more powerful and efficient performance.
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Official graphic representing the Apple watchOS 26 software update
This technical detail was revealed by Apple in a video for developers explaining what’s new in watchOS 26. The main point is that the Apple Watch Series 9, the upcoming Series 10, and the Apple Watch Ultra 2 will shift from their current architecture, known as arm64_32, to the full arm64 standard.
Understanding the Technical Shift: arm64_32 vs. Full arm64
Think of an architecture as the fundamental design of the watch’s processor and how it handles information. For years, the Apple Watch has used a modified version of the standard 64-bit architecture, called arm64_32. This version was specifically tweaked for devices with limited memory, like a watch. It used 32-bit “pointers,” which are like the addresses the processor uses to find data in memory. Using 32-bit addresses kept things compact, saving precious memory space.
The full arm64 architecture, which powers iPhones, iPads, and Macs, uses 64-bit pointers. This allows the processor to access a much larger range of memory and generally handle data more efficiently. It also provides access to more temporary storage locations (registers) that the processor uses for calculations, which can speed things up. Moving to full arm64 brings the Apple Watch in line with Apple’s other devices, simplifying development tools and making it easier for developers to create more complex apps.
Which Apple Watch Models Are Getting This Upgrade?
The technical upgrade to full arm64 in watchOS 26 applies to:
- Apple Watch Series 9
- Apple Watch Series 10
- Apple Watch Ultra 2
Older models will continue to use the arm64_32 architecture. These include:
- Apple Watch SE (2nd generation)
- Apple Watch Series 8
What This Means for Your Apple Watch Experience
For users with the latest watches, this move to full arm64 isn’t something you’ll likely see directly in a setting, but you might feel it over time.
- Potentially Snappier Performance: The full arm64 architecture is inherently more capable. While watchOS is already optimized, this change provides a foundation for apps to run more efficiently, potentially leading to faster load times and smoother interactions, especially as apps become more sophisticated.
- Future-Proofing: Aligning with Apple’s other platforms means the Watch can better leverage future software improvements and development tools. This architecture is built for the long haul.
- Enabling More Advanced Apps: Access to more memory and registers could allow developers to build more complex, computationally intensive apps on the watch in the future – perhaps things like more advanced health analysis directly on the device or richer games.
For users with older models staying on arm64_32, your watch will continue to function as expected. Existing apps will still run. The difference is that these models won’t benefit from the architectural advantages of full arm64.
Implications for App Developers
This change is a significant one for developers building watchOS apps. They now need to ensure their apps work correctly on both architectures: arm64 for the newer watches and arm64_32 for the older ones.
Fortunately, Apple’s development tool, Xcode, is designed to handle this automatically. Developers just need to set their project correctly, and Xcode will build versions of the app package (called “binaries”) for both architectures.
Apps built previously only for arm64_32 will still run on newer watches running watchOS 26 thanks to compatibility layers. However, Apple is encouraging developers to update and re-compile their apps specifically for the native arm64 architecture to get the best performance on the new hardware. It’s expected that support for the older arm64_32 architecture on Apple Watch will eventually be phased out as the older models are retired, bringing the entire Apple Watch lineup onto the modern standard.
Conclusion
The move to full arm64 in watchOS 26 for the latest Apple Watch models is a foundational technical upgrade. While not immediately visible, it sets the stage for enhanced performance and potentially more capable applications on your wrist in the future. It also simplifies the long-term development path for watchOS by aligning it with Apple’s other platforms. This change ensures the Series 9, Series 10, and Ultra 2 are built on the most current and powerful architecture for years to come.
Interested in discussing the future of watchOS or have questions about your current Apple Watch? Join the conversation in our Apple Watch Forums!
