Teardown shows Apple Watch S1 chip has custom CPU, 512MB RAM, 8GB storage

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At the heart of the S1 is an Apple-designed processor, labeled the APL 0778, as discovered by ABI Research. The Broadcom chip is a BCM43342, capable of Wi-Fi, Bluetooth, NFC, and even FM radio, although the FM functions aren't actually used. Supporting the NFC capabilities, used for Apple Pay, are an NXP-made controller and a signal booster from AMS.

The device has 512 megabytes of Elpida RAM, which is paired with 8 gigabytes of storage from SanDisk and Toshiba. The Watch stores relatively little on-board, instead pulling most data from a paired iPhone. Users can, however, save a music playlist to their Watch for unpaired listening, and native third-party apps are planned for later this year.

Accelerometer and gyroscope functions are handled by an STM chip, while an ADI controller handles touch gestures. Finally, power is routed through a Dialog power management unit and an IDT-made wireless charger.

ABI commented that the S1 is an "obvious variation from Apple's smartphones," compressing many parts normally reserved for those devices. A recent Chipworks X-ray of the S1 showed that the STM chip is the first in an Apple product that merges accelerometer and gyroscope functions.