Mac on ARM: why Apple switched to its own processors, what is the difference with Intel and what will change for users

Old Macs will not stop working overnight, macOS will support both types of processors, and the transition will take more than one year.

A13 Bionic – Apple’s flagship processor of its own design, which is considered the most productive in the smartphone market. Frame from Apple video

At the WWDC 2020 Developers Conference on June 22, Apple announced that it would switch to proprietary processors on all Mac computers, including the MacBook Air, Pro, iMac, and Mac Pro. Within two years, the company will abandon Intel’s ready-made solutions and will begin to use chips based on the ARM architecture.

The first computer on its own processor Apple wants to release at the end of 2020, and macOS Big Sur already supports new chips. we explains why Mac owners at Intel do not have to worry about why Apple needed the transition and how it will happen.

ARM and SoC – what is it and what are their features

SoC stands for “system on a chip” (System-on-a-Chip), they are also called “single-chip” systems. Often, such processors are used in portable electronics due to their compactness, low power consumption and economy.

Processors for PCs usually also contain one chip, but only with the processor itself. At the same time, in one SoC there can be many components at once, including graphics, modem, separate modules for specific tasks and not only.

Apple has been using SoC chips since at least the first iPhone in 2007. The company released its first iPhones with Samsung processors, then licensed ready-made ARM solutions, and since 2012, it has been developing ARM-based chips and plans to install them in new Macs.


A4 – Apple’s first ARM processor

ARM chips differ from Intel in architecture. The basis of the operation of any processor is a set of commands – elementary operations that the chip is able to perform, for example, moving data or basic calculations. The programming language on such instructions is called assembly language.

ARM processors belong to the RISC architecture (“reduced instruction set computing”, reduced instruction set computing), the acronym even stands for Advanced RISC Machine. And x86-chips from Intel belong to the CISC-architecture (“calculations with a complex set of instructions”, complex instruction set computing).

The goal of RISC is to reduce everything to such elementary commands that any task can be performed in one processor cycle, that is, in a time period synchronizing the execution of all operations. CISC processors are based on the opposite principle: they use more complex instructions and execute them for several clock cycles.

ARM chips are aimed at maximum energy efficiency, while Intel or AMD solutions are aimed at peak performance.

If the CISC processor needs to multiply two numbers, it is enough to run one MULT command: it will load the numbers from memory, multiply them and save the result in the desired cell. In the case of the RISC chip, the same operation will require much more steps: first you need to move the numbers from the registers to the executive block with a separate LOAD command, then multiply them with the PROD command, and then use STOR to place the result in the desired register.

In this case, it might seem that CISC is a more efficient architecture because its teams look simpler. But this impression is misleading: processors of this type perform tasks in several clock cycles, and RISC chips always perform each task in one clock cycle. Thus, a hypothetical multiplication command can take the same number of cycles for both architectures.

CISC has its advantages. First of all, they are faster at translating high-level programming languages ​​like “C” into assembly language that the machine understands. In addition, CISC commands are more complex and allow you to perform several operations at once with no restrictions on processor cycles. Therefore, such processors are popular in desktop PCs or laptops, where you do not need to save energy or space.

However, the instructions of all processors use transistors, and since CISC-chips have more complicated instructions, they occupy more physical space than RISС. From this, the key advantages of RISC chips follow – they have fewer transistors, which means they take up less space, consume less energy and generate less heat.

Intel Core 2 Duo and Texas Instrument OMAP 3630 ARM chip User photo of  World Super Cars

These features made ARM the ideal choice for portable electronics with its strict heat dissipation (TDP) requirements of 3.5 watts and the absence of active cooling. While Intel won high-performance systems on processors with a TDP of 100 watts, ARM-based chips increased power, remaining a very energy-efficient solution.

At the time of this writing, the fastest supercomputer in the world was running on ARM processors. In this case, until now, ARM is not widely used in desktop systems, and Intel processors historically perform worse in conditions of low heat dissipation.

Why Apple abandoned Intel

According to Bloomberg sources, the reason for Apple switching to its own processors in the Mac was the problem with Intel’s performance increase. The interlocutors of the publication claimed that because of this, the company has to revise plans for the production of macbooks and even abandon some devices.

In recent years, Intel has really experienced performance gains. Largely due to the fact that the company got stuck on the old manufacturing process – this indicator reflects the density of the processor “packaging”: the lower the value, the more transistors are placed on the chip.

Intel still produces processors using the 14-nm process technology – at the level of 2014. During this time, as ARM-chips for mobile devices have gone from 20 nm to 7 nm, and in 2021, manufacturers are going to switch to the 5-nm process technology.

In addition, Apple has been reducing its reliance on third-party vendors and third-party technologies for many years. This is most evident in iPhones: at first they used Samsung processors, Qualcomm modems, Imagination Technologies graphics, and as a result, Apple began to develop all these components itself.

The transition to ARM on Mac is also beneficial for Apple because the company will gain full control over the key hardware component. Previously, Apple received a ready-made chip from Intel, with which it could not do anything else – all the other processes had to be built around it.

Unlike Intel or AMD, ARM does not sell the processors themselves, but an architecture license. Therefore, Apple will not be limited to another’s technological process and will be able to make a chip for its own needs – as is the case with iPhones.

The company, during a presentation at WWDC 2020, explained that it wants to achieve lower power consumption and at the same time increase productivity. As conceived by Apple, Mac computers with their own chips should surpass both current laptops and desktop solutions – they will consume less power than laptops, but will work faster.


Apple presentation chart at WWDC 2020

So far this is a bold statement that cannot be verified, but in a review on the iPad Pro with Magic Keyboard, I wrote that Apple tablets have already caught up with the basic versions of macbooks in everyday tasks. In some ways, they turn out to be even more convenient: for example, they do not overheat and do not start to slow down due to poor cooling, and they have approximately the same operating time, although the iPad Pro is much more portable.

ARM architecture can really fix problems and improve macbooks in many ways. At a minimum, you can count on the lack of throttling (processor slowdown) due to poor cooling, much more powerful integrated graphics and getting rid of overheating.

In addition, the use of SoC will significantly optimize the design of the macbooks. Many components that now need separate hardware will be built into the chip itself, and the cooling will become more compact: that means free up space in the case – Apple can increase the battery or make devices even smaller.

For MacBooks, all these changes can only benefit: in recent years, the devices seemed to stagnate and received less and less noticeable innovations. In addition, thanks to its own processors, Apple may begin to introduce into the device unique features that are available only on the Mac.

During the presentation, the company already showed a small teaser on what to expect from the new chips: the Neural Engine neural processor and machine learning accelerators, high-quality camera image processing, performance controller, high-performance DRAM, cryptographic accelerators and more.


New features of Apple’s own processor in Mac Image of Apple

Perhaps the main advantage of switching to native chips for Apple is the closure of the ecosystem. Mac remained the only devices of the company, during the creation of which it depended on someone else and did not control the entire hardware and software.

Now all Apple products will have a single architecture, which means that development for the entire ecosystem will be simplified. It will be possible to create cross-platform applications that will work simultaneously on macbooks, iPhones and iPads without additional modifications.

There is another non-obvious plus for Apple – the reduction in the cost of components. If before that the company depended on Intel prices, now it will save significantly. On the other hand, the cost of research and development of their chips can block this money.

The main issue remains productivity: there is no consensus among experts which architecture is better, because they are tailored for different applications. One can only speculate how well the new ARM chips will work in Macs, but Apple has already proved by the example of iPhones that she is able to provide high performance if she creates both hardware and software.

Analysts suggest that on laptops, the company will strive to strike a balance between performance and power consumption. And for more massive desktop computers, Macs are likely to release a separate line of processors with maximum power.

So far, the only way to understand at least a little how the new Macs will work is the Development Transition Kit – a special version of Mac mini on the A12Z processor, like the iPad Pro 2020. The device was released only for developers, not everyone can get it, you need to pay $ 500 for it. and return the sample at the end of the year.


A12Z is ​​the only Apple processor to release Mac mini

All developers who received DTK signed the NDA (non-disclosure agreement), but some apparently violated it. So on the net were the results of the first tests: judging by them, not the latest Apple chip that was created for tablets, in compatibility mode, shows results close to the 2020 MacBook Air on an Intel Core i5 processor.

At the same time, Apple is not the first in the market to start using ARM processors on desktop devices. Microsoft switched to its own chips in 2019 with the release of the Surface Pro X and Surface Laptop 3 with an SQ1 processor, created in conjunction with Qualcomm.

However, as the journalists who used the devices noted , they work more slowly than devices using Intel processors. In addition, due to the support of two architectures, developers are paying more attention to the more common one, so technical problems may arise from Surface to ARM.

Judging by the first tests, the Development Transition Kit even on a processor two years ago, emulating code, showed a better result than Surface Pro X, which executed it natively.

How will the transition happen and what should users expect

This is not the first time Apple has changed processors in the Mac: it has already happened twice – in 1994 and 2005. Before Intel, the company’s computers already even ran on RISC chips – before, the company used Power PCs, which they created together with Motorola and IBM.

They were abandoned in 2005 when Steve Jobs at the next WWDC announced the transition to Intel. The reason was called the same processor performance limits for future products, as well as problems with heat production and energy consumption.


Steve Jobs announces the transition to Intel processors in 2005. Shot from Apple’s presentation at WWDC 2005

Apple still worked on the process of changing chips, so it’s very easy to imagine what will happen in the near future. During a presentation at WWDC 2020, Tim Cook announced that the transition will take two years, while the first computer with new processors will be released at the end of 2020.

It was almost the same with the Power PC: then the transition should have taken 1.5 years, but in the end it happened a little more than in a year, and the first device on Intel was released in January 2006. Probably, now the process will be faster than announced in the company.

At the same time, Apple claims that it has not completely abandoned the Intel platform and is developing devices with a plan to release them “for years to come”. Those who have already bought a Mac on Intel are hardly worth worrying about: they will receive support for both macOS Big Sur and the next versions of the system – Power PCs ceased to support only three years after switching to Intel.

Developers obviously will not give up Intel platform yet: now all applications are adapted only for working with it. At the time of the transition, Apple encourages the use of Universal and Rosetta tools, known even from the rejection of the Power PC.


Universal 2, Rosetta 2 and Virtualization for Linux

Rosetta 2 is a new version of the team translator. She will adapt the application code to the new Apple chip architecture on the fly during the installation process. Thus, new computers will support all old applications, but in emulation mode – that is, with reduced performance and without the support of new hardware capabilities.

The Universal 2 tool will support Intel-based computers when developers reorient to Apple chips. They will be able to create applications that will use all the new features of the Mac, but will also support older devices on Intel.

For full native support for new chips, software developers will have to release new versions of programs. And although Apple says that most teams will be able to do this in a few days, most likely, many large companies that produce professional programs will take more time.

Some software has already been adapted: during the presentation, Apple announced that Microsoft is working on Office updates with support for new chips, and Word and Excel are already using Apple Metal graphics for rendering. The company works with Adobe, which is going to adapt its programs among the first. During the presentation, Apple even showed how smoothly the Lightroom works and how easy it is on the new Macs to see the details of a 5 GB file in Photoshop.

It is hard to say how the transition to new processors for Mac will end. But as experience from past transitions showed, computers only got better. In any case, owners of current Macs should not be afraid, their devices will not stop working in the near future.

Those who were just about to buy Apple computers will soon be able to choose between two options, but keep in mind that Macs with Intel will at best support a few more years, and Macs with Apple chips will not support Windows through Boot Camp. But Mac computers with Intel chips will not receive exclusive features, and at some point they simply won’t receive a new version of macOS


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