Some observers were surprised that Apple's big news in transitioning Macs away from Intel processors didn't refer to the move as a migration to "ARM." Instead, Apple's chief executive Tim Cook introduced it as a move to Apple silicon. Here's why.
Apple silicon is a head and shoulders above ARM
The A12Z chip that Apple is currently using in its latest LiDAR iPad Pro and its first generation Apple silicon chip in the Mac mini developer transition kit does incorporate ARM CPU cores. But that ARM Architecture CPU is not the most significant reason Apple is moving away from Intel's chips on Macs.
Apple alluded to this in referring to its own custom silicon as being an "SoC," or System on a Chip. Over the past decade, Apple has developed a series of SoCs that incorporate essentially an entire logic board of chips that a typical PC would require into a single chip that can be mass produced and used across multiple devices from its iPhone, to iPad, to Apple TV and even HomePod.
The baseband modems supplied by Qualcomm for handling connectivity to mobile networks also incorporates an ARM processor core, but most of the value of these chips comes from the total package of components and proprietary software, not merely the standards-based CPU core serving at its center.
In some respects, Apple's use of ARM cores in its SoCs is similar to its use of Unix in the OS itself. Both are effectively specifications that standardize the operations of low level technology layers. In the same way that Macs are more than just Unix systems, Apple's SoCs are more than just ARM processors.
As with Qualcomm's modems, the customizations, optimizations, and additional layers of proprietary work that Apple adds to its A-series SoCs results in a package that's significantly more valuable than its base components.
That reality is reflected in Apple's custom silicon being a lot more than just an "ARM chip," and helps to explain why Apple's SoCs have increasingly outperformed other ARM-based SoCs developed by Qualcomm, Nvidia, Samsung, and others.
