Apple Boots Intel Silicon to Make Way for Its In-House Processors. What Spurred the Shift?

June 26, 2020 by Tyler Charboneau

It turns out, this change has been a long time coming.

This week, Apple announced plans to outfit select Mac computers with an in-house Arm processor. The shift ends Apple's fourteen-year reliance on Intel's processor platform.

How did Apple reach this decision and where do Macs go from here?


Apple’s Processor History

This isn’t the first time Apple has moved between architectures. Long-time followers will remember the move from Motorola 68000 CPUs in the 1990s. Then, in 2005, the company binned PowerPC in favor of Intel. Merely seven months later, Apple unveiled its maiden lineup of Intel-based Macs at MacWorld Expo 2006. This was a swift change in its own right. 

However, the computing world has since matured substantially—giving consumers and professionals time to firmly entrench themselves in key camps. These revolve primarily around software, including dependence on suites from Microsoft, Adobe, and others. Intel's x86 architecture also enables Bootcamp and dual-booting of Linux distributions. 


Macs built on Apple silicon

Macs built on Apple silicon may provide a sweet spot in performance and power consumption for both desktop computers and notebooks. Screenshot used courtesy of Apple

Most Mac users leverage macOS for the vast majority of their activities. A vocal minority, however, will wonder how the transition will impact their ability to run critical applications. Arm will be a tougher sell to professionals (and some students) than any prior architecture. Apple does have half a year to state their case. MacOS developers can also begin writing Arm applications today using the Xcode 12 beta, alongside macOS Big Sur. 

The 13.3-inch MacBook Pro and iMac will receive the new A12Z CPU by year’s end. Remaining Macs will gradually transition throughout 2021. 


Issues with Intel

Intel’s run with Apple has been mighty, though not entirely trouble-free. Apple’s customers have often sounded off against both companies due to delays in securing next-generation processors. It wasn’t entirely uncommon for Macs to lag a CPU generation behind their Windows counterparts. This dependence on Intel’s pacing was a limitation. 

Additionally, each successive Intel generation saw diminished performance gains—not entirely abnormal, though buyers expected more. The traditional “tick-tock” development cycle of Intel CPUs changed. Since Sandy Bridge’s 2011 market launch, Intel has struggled to consistently engineer such large gains in raw performance and efficiency. A lack of meaningful competition also allowed the company to rest slightly on its laurels. 


AMD Outpaces Intel

Today, chief rival AMD has caught up to Intel. The introductions of Ryzen and Threadripper have helped AMD match or surpass Intel in performance per watt.

So, why not choose AMD instead?

We must acknowledge some known unknowns. While AMD is typically the better value pick for consumers, we don’t know how that changes at scale. It could be that Apple’s requirements are too ambitious, costs are too high, or manufacturing capability is insufficient. Perhaps Apple just couldn’t strike the right deal with AMD. 


Apple's Eye on Security

Security has always been a top concern at Apple. The Meltdown and Spectre vulnerabilities had companies scrambling to find a patch. Apple and others had to implement their own fixes while working with Intel on additional code changes. 


A Slowburn Transition Away from Intel

Finally, the transition has been a slow burn. François Piednoël, former Intel principal engineer, claims that major QA problems with their Skylake CPU kicked off the transition. It wasn’t long before Apple filed numerous complaints about bugs and other issues. This is the word of one engineer, though.

Regardless, Apple has made major strides in the three years since—encouraged by massive advancements in their A-series chips.


Apple SoCs for the iPhone

A timeline of Apple's SoC upgrades. Screenshot used courtesy of Apple


The latest A13 Bionic chip outpaces Intel’s i7-8565U per Geekbench 4 in both single-core and multi-core performance. These numbers don’t always equate to real-world results, though the results are highly impressive. 


Looking at Arm and the A12Z

Because Apple uses the A-series in the iPhone, iPod Touch, and iPad, adopting this architecture for the Mac would aid consistency. This unified platform makes it easier for developers to create new apps. Apple’s Universal 2 binaries will allow apps to work with Arm and Intel.


The core characteristics of Apple's new Arm-based processor

The core characteristics of Apple's new Arm-based processor. Screenshot used courtesy of Apple

The App Store currently lags behind in app availability, due largely to OS fragmentation and Apple’s fee structure. This unified development—alongside potential policy changes—could be a boon for App Store publishing. Apple is pushing strongly into the services and gaming realms, so this isn’t surprising. 


The Goal for In-House CPUs and GPUs

Apple’s goal is to create CPUs (and in-house GPUs) with unrivaled performance per watt.

In his WWDC 2020 presentation, Vice President of Hardware Engineering Johny Srouji explained the A12Z’s development philosophy.

Laptops traditionally trade performance for power conservation, whereas desktops perform better with higher power requirements. Srouji states that Apple is crafting CPUs that avoid this tradeoff—performing exceptionally well with conservative power draw. The company’s A-series performance numbers have been reason enough to switch. 


Apple's SoCs Under Development

Apple’s upcoming SoCs will also include a laundry list of packaged technologies. These are made possible due to tight hardware-software integrations. Here are some highlights: 

  • Machine learning accelerators
  • Neural engine
  • Advanced power management
  • Secure enclave (adapted from previous devices)
  • High-performance and high-efficiency CPU cores
  • High-performance GPU (helpful for gaming and robust applications)

It’s notable that the hardware team is designing a family of A-series SoCs, as opposed to a one-size-fits-all solution. This approach will aid device-specific performance tuning.

Srouji also boasts about video display and image processing advancements. With the global ML market expected to grow by 44% annually through 2022, Apple is positioning the Mac as a top-notch machine learning (ML) development platform.

Apple is making it easy to run both Linux and Docker environments—with the A12Z and its successors. 


The Key Is in the Core

Apple’s Arm advantage has always resided within its cores. Like those before it, the A12Z will include sets of performance or efficiency cores that activate on a task-by-task basis. Integrated GPU cores also kick in for graphically-rich operations.

A Notebook Check report, later confirmed by TechInsights, has revealed extreme similarities between the iPad Pro’s A12X GPU setup and the A12Z’s:


A side-by-side comparison of Apple’s A12X and A12Z

A side-by-side comparison of Apple’s A12X and A12Z. Image used courtesy of TechInsights 

Both the A12X and A12Z possess eight GPU cores. However, the A12X only has seven active cores. The A12Z has eight. We can see the A12Z isn’t exactly all-new in its execution—it’s an exceptional proof of concept for Apple with some added graphical prowess.

For what it’s worth, the Developer Transition Kit includes an A12Z-powered Mac Mini with 16 GB of RAM. This chip does mate well with hardware typically found in notebooks and desktops.


Future Production

The forecast for the A-series transition does seem promising. Apple is betting big on its success; after all, the A13 Bionic is over 100 times more powerful than the A4. The iPad Pro also delivers over 1,000 times better graphical performance than it did ten years prior.

Why shouldn’t these benefits extend to the Mac?

The company has been producing Arm chips for years now—having “shipped over two billion in the last ten years.” The sales from the iPhone, iPad, and Apple Watch together dwarf Mac sales. Billions of coprocessors have also been produced. This scaled production should thus be simple. 

Apple will face many questions in the near future. It can best provide answers by doing what it has always done best—producing SoCs and software that work together harmoniously.