It's no longer hard to find 64-bit processors in smartphones. In smartwatches, though, they're still a rarity -- and ARM wants to change that with its new Cortex-A35 processor design. The architecture promises the most energy-efficient 64-bit mobile chips yet, sipping 32 percent less power than the mid-range A53 even as it outruns the Cortex-A7 it's meant to replace (6 to 40 percent faster). It's extremely scalable, too. You can build full-fledged quad-core chips for entry-level smartphones, but you can also strip things back to make tiny chips for watches and activity trackers.
The first A35-based devices aren't likely to ship until late 2016, and it's too soon to say who's lining up to use the design. However, the technology holds a lot of promise for wearables and entry-level smartphones. While 64-bit isn't a cure-all (it doesn't automatically make devices faster, for instance), it unlocks the door to apps and features that depend on particularly complex number-crunching, like tougher encryption. You may well see smartwatches next year which do things that aren't even feasible today.