The new S9 SiP chip is included with every Apple Watch Series 9 model, but the most recent analysis indicates that this chip is not mass produced using TSMC's state-of-the-art 3nm "N3B" process, which was also utilized to create the A17 Pro and M3 line. The 'System in a package' of the smartwatch, on the other hand, is based on Apple's A16 Bionic, the previous generation processor found in the new iPhone 15 and iPhone 15 Plus. The S9's utilisation of an iPhone SoC as its foundation highlights the scalability of the tech giant's chip architecture and is an economical approach to designing silicon for multiple products.
The S9 has a lot fewer CPU and GPU cores than the A16 Bionic, which should reduce the Apple Watch Series 9's power usage.
Located in larger products like the iPhone, the A16 Bionic has four power-efficient cores and two high-performance cores. Although there is a 5-core GPU built into the chipset, it is absurd to think that all of those cores could fit into the same packaging as the S9. Instead, Apple's Apple Watch Series 9 SoC has a single GPU core and a dual-core CPU. This means that the S9 has fewer CPU and GPU cores overall.
Although the Apple Watch Series 9 is a completely different product class than the iPhone 15 and iPhone 15 Plus, it does not mean that it will have the same punch as the A16 Bionic. According to EETimes' analysis, Apple uses a scalable architecture that significantly reduces design, tape-out, and production costs. This is because each chipset is designed to be customized for a specific product, but it can also be scaled up to fit a more capable product, like the iPad Pro or Mac, and vice versa.
For example, the analysis claims that Apple's M3, M3 Pro, and M3 Max are based on the A17 Pro, which has a larger die while being mass produced on the 3nm process, much like the S9, which is based on the A16 Bionic. Why is there not a single 3nm chip in any of the Apple Watch Series 9 models? That most likely has to do with how expensive it is to produce this silicon.
With the Apple Watch Series 9 offering fewer features and functionality than the other product ranges, it makes little sense to use a cutting-edge manufacturing process for the S9. The tape-out cost for the M3, M3 Pro, and M3 Max is reportedly $1 billion. We should hopefully learn that TSMC's new 3nm "N3E" technology is being used to give the S10 SiP, which will make its debut with the Apple Watch Series 10, more sophisticated capabilities.
