The A9 SoC inside the iPhone 6s comes from two different vendors (Samsung and TSMC) using two different FinFET processes (14nm and 16nm, respectively). We test both versions to see if there's any power or performance differences.
Now that the veil of secrecy surrounding the iPhone 6s and 6s Plus has lifted, some interesting details have emerged. One of the more tantalizing discoveries was made by Chipworks, when it revealed that Apple is dual-sourcing its A9 SoC (System on a Chip) from Samsung and TSMC.
Sourcing components from multiple vendors is a common practice among OEMs, especially for memory chips such as RAM and NAND. Apple routinely dual-sources the IPS screens for its iPhones, and Samsung frequently uses entirely different SoCs, camera sensors, and baseband processors, which differ in performance and features, in its smartphones depending on which region they're sold.
What's unusual in this case, however, is that Samsung is using its 14nm LPE (Low Power Early) FinFET process, which it also uses for the Exynos 7420 SoC, while TSMC is using its own 16nm FinFET process, resulting in two different versions of the A9 SoC with different die sizes.