Apple Watch Series 12 and Ultra 4 May Have Hidden 128GB Flash Storage

A Chinese hardware researcher claims the Apple Watch Series 12 and Ultra 4 use a 128GB NAND flash die despite officially offering only 64GB of storage. The reason for the limit is unclear — Apple may reserve part of it for sensor data or wear leveling. A similar case occurred with the M4 iPad Pro, which had 12GB of physical RAM but only 8GB accessible.

• The watches use a 128GB NAND die despite 64GB of advertised storage
• A 128GB storage profile is tied to the T8320 chip
• The M4 iPad Pro similarly had 12GB physical RAM with 8GB usable
• Apple has not explained the capacity limit