Why Apple Silicon is Faster Than Intel & AMD?

While Intel was playing at the top of the world computer chipset market for decades, AMD became a serious competitor from a couple of years ago with the dramatic improvement of the multicore performance and the power to performance ratio of their Ryzen series of chips.

But Apple washed out all the topics of these two manufactures with the announcement of their M series of ARM architectured chips for their Mac computers. ARM (Advanced RISC Machine) is a family of instruction set architecture that is based on RISC developed by Arm Ltd. So, it makes sense that the M1’s also RISC based.

If you are confused about the connection between ARM and RISC, please click here for more details.

Apple has been designing its A-series chips that have been used in every iPhone and iPad for a decade. So, M1 is not the beginning of RISC design. Apple has plenty of experience and a long history that is spent on R&Ds to refine the architecture. In this case, we can conclude M1 is an outcome of Apple’s masterclass engineering expertise on the RISC.

The truth is, M1 is not so impressive in terms of single-core frequency scaling, reaching a 3.10 GHz of maximum when Intel Core i7–1185G7 can boost up to 4.8GHz while Intel i9–11900K boosts up to 5.3 GHz. However, we can see the M1 defeats many of the top Intel and AMD-based pcs in most cases in real life.

Let me show you some simple aspects of how it happens with some simple terms of computer architecture and CPU design.

The computer systems have been designed under two main Computer architectures mainly based on the control unit design, the nature of the instructions that have been used, and how it executes, which is known as RISC (Reduces Instruction Set Computer) and CISC (Complex Instruction Set Computer).

Characteristics of,

RISC,

o Format of the instructions is uniform (have fixed length).

o Have a small subset of pre-defined instructions.

o Less flexibility of instructions(pre-defined), but execution is faster.

o Uses simple hardwired control unit design.

CISC,

o Format of the instructions is varied (not fixed length).

o Have a large set of instructions.

o Higher flexibility of instructions (not pre-defined), but execution is slower.

o Uses complex microprogrammed control unit design.

Since the M1 is RICS based, its 4-byte fixed-length instructions allow to have more decoders to decode the instruction at the middle of the execution cycle. It becomes simple to load many instructions at the same time and explore opportunities to execute CPU-intensive tasks in parallel. But Adding more decoders in the CISC-based x86 chips such as Intel and AMD is very complex since don’t have a fixed length for instructions.

Apple M1 also includes a very large reorder buffer, which is the store of instructions that are fetched and analyzed for possible parallel execution. In addition to that, most intensive/heavy tasks are optimized for parallel execution in the M1. It means the M1 does more parallelism at the chip level efficiently than Intel and AMD.

On the other hand, M1 is not just a CPU. It is a collection of many chips housed inside one silicon container. Generally, those are known as System on Chip (SoC) which contains CPU, GPU, input/output controller, and neural engine in one single chip, even M1 contains main memory (RAM) modules inside. So, the time is very less to complete a task that involves all the components than the usual system because the time is very less that taken to communicate among these components. It is a lot more efficient on both sides of execution speeds and power usage. So, heat dissipation is also very less even when running heavy tasks in this SoC.

Finally, the efficient parallelism and more efficient SoC design are the main actors behind the term of the incredible performance of the Apple silicon chips.

If you are willing to surf more into Apple’s journey of ARM chips through decades, you can refer to the following write of an expert.

Apple’s Humongous CPU Microarchitecture

let’s take a look at another important aspect of a related topic in the next.

Thank you!