Apple M1
The Apple M1 is an ARM-based system on a chip (SoC) designed by Apple Inc. as a central processing unit (CPU) and graphics processing unit (GPU) for its Macintosh desktops, MacBook notebooks, and iPad Pro tablets. The new chip also brought Apple's third change to the instruction set architecture used by Macintosh computers, 14 years after they were switched from PowerPC to Intel. Apple claims the chip has the world's fastest CPU core "in low power silicon" and the world's best CPU performance per watt.

The M1 was released in November 2020, followed the next year by the Apple M1 Pro and M1 Max versions. These differ largely in size and the number of functional units: for example, the original M1 has about 16 billion transistors; the largest M1 Max, 57 billion.

The M1 runs on Apple's macOS and iPadOS operating systems. Initial support for the M1 SoC in the Linux kernel was released in version 5.13 on June 27, 2021.

M1 based devices are sold with 8 or 16 GBs of RAM, is shared among all compute units, and is not upgradeable.  

The initial versions contain an architectural defect that permits sandboxed applications to exchange data, violating the security model.

Design

CPU 
The M1 has four high-performance "Firestorm" and four energy-efficient "Icestorm" cores, providing a hybrid configuration similar to ARM DynamIQ and Intel's Lakefield and Alder Lake processors. This combination allows power-use optimizations not possible with previous Apple–Intel architecture devices. Apple claims the energy-efficient cores use one-tenth the power of the high-performance ones. The high-performance cores have an unusually large 192 KB of L1 instruction cache and 128 KB of L1 data cache and share a 12 MB L2 cache; the energy-efficient cores have a 128 KB L1 instruction cache, 64 KB L1 data cache, and a shared 4 MB L2 cache. The SoC also has a 16MB System Level Cache shared by the GPU.

GPU 
The M1 integrates an Apple designed eight-core (seven in some base models) graphics processing unit (GPU). Each GPU core is split into 16 Execution Units, which each contain eight Arithmetic Logic Units (ALUs). In total, the M1 GPU contains up to 128 Execution units or 1024 ALUs, which Apple says can execute up to 24,576 threads simultaneously and which have a maximum floating point (FP32) performance of 2.6 TFLOPs.

Other features 
The M1 uses 4,266 MT/s LPDDR4X SDRAM in a unified memory configuration shared by all the components of the processor. The SoC and RAM chips are mounted together in a system-in-a-package design. 8 GB and 16 GB configurations are available.

The M1 contains dedicated neural network hardware in a 16-core Neural Engine, capable of executing 11 trillion operations per second. Other components include an image signal processor (ISP), an NVMe storage controller, Thunderbolt 4 controllers, and a Secure Enclave.

Supported codecs include H264 and H265 (8/10bit, up to 4:4:4), VP9, and JPEG.

Performance and efficiency 
The M1 recorded competitive performance and efficiency in popular benchmarks (Geekbench 5, Cinebench R23).

The 2020 M1-equipped Mac mini draws 7 watts when idle and 39 watts at maximum load, compared with 20 watts idle and 122 watts maximum load for the 2018, 6-core Intel i7 Mac mini. The energy efficiency of the M1 doubles the battery life of M1-based MacBooks from the previous Intel-based MacBooks.

At release, the MacBook Air (M1, 2020) and MacBook Pro (M1, 2020) were considered to be the fastest MacBooks produced by Apple.

Gallery

Products that use the Apple M1 
 MacBook Air (M1, 2020) - base model has 7-core GPU
 Mac Mini (M1, 2020)
 MacBook Pro (13-inch, M1, 2020)
 iMac (24-inch, M1, 2021) - base model has 7-core GPU
 iPad Pro, 11-inch (3rd generation) (2021)
 iPad Pro, 12.9-inch (5th generation) (2021)

Problems

USB power delivery bricking 

After its release, some users who charged M1 devices through USB-C hubs reported bricking their device. The devices that are reported to cause this issue were third-party USB-C hubs and non-Thunderbolt docks (excluding Apple's own dongle). Apple handled this issue by replacing the logic board and by telling its customers not to charge through those hubs. macOS Big Sur 11.2.2 includes a fix to prevent 2019 or later MacBook Pro models and 2020 or later MacBook Air models from being damaged by certain third-party USB-C hubs and docks.

Hardware errata 

The M1 chip has errata given the name "M1RACLES". Two sandboxed applications can exchange data without the system's knowledge by using an unintentionally writable processor register as a covert channel, violating the security model and constituting a minor vulnerability. It was discovered by Héctor Martín Cantero.

See also
 Apple A14
 Rosetta 2
 Apple M1 Pro and M1 Max
 Universal 2 binary

References

External links 
 

ARM architecture
Computer-related introductions in 2020
Apple silicon
64-bit microprocessors