Our friends at Chipworks have spent the last two weeks hard at work cracking the S1. Here's what they found:

The Apple S1 System in Package (SiP) is composed of over 30 individual components, attached to a single board that is then overmolded with a silica or aluminum composite resin—similar to conventional IC packaging, but for an entire board.

At the heart of the S1, Apple's new APL0778 processor is fabbed on Samsung's 28 nm LP process.

This represents a slight step backward from Apple's 20 nm A8 processor, which shipped with the iPhone 6 in September. Power efficiency would seem to be, if anything, even more critical in the Apple Watch than in the iPhone. With Samsung now fabbing chips on an even smaller 14 nm scale, we expect improved battery life in the next Apple Watch.

Check out Chipworks' full analysis here.