Why Apple Will Switch to ARM-Based Macs

This post originally appeared at MattRichman.net and was re-posted at Tech.pinions with Matt’s permission.

When Steve Jobs announced the transition from PowerPC to Intel processors in 2005, he revealed something that, in hindsight, seemed obvious to everyone who didn’t anticipate the switch:

There are two major challenges in this transition. The first one is making Mac OS X sing on Intel processors. Now, I have something to tell you today: Mac OS X has been leading a secret double life for the past five years.

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We’ve had teams doing the “just in case” scenario. And our rules have been that our designs for OS X must be processor independent, and that every project must be built for both the PowerPC and Intel processors. And so today, for the first time, I can confirm the rumors that every release of Mac OS X has been compiled for both PowerPC and Intel. This has been going on for the last five years.

There’s not a doubt in my mind that if you substitute Intel for PowerPC and ARM for Intel, what Steve Jobs said then holds 100 percent true today, word for word. Mac OS X designs must be processor independent, every project must be built for both Intel and ARM processors, and each Mac OS X release in the last five years has been compiled for both Intel and ARM.

Somewhere on Apple’s campus, ARM-based Macs are already running OS X.

User Experience Would Improve

In his iPhone 5S review, Anand Shimpi compared the Apple-designed A7 processor with Intel’s fastest tablet chip at the time. He wrote:

For our cross-platform CPU performance tests we turn to the usual collection of Javascript and HTML5 based browser tests. Most of our comparison targets here are smartphones with two exceptions: Intel’s Bay Trail FFRD and Qualcomm’s MSM8974 Snapdragon 800 MDP/T. Both of those platforms are test tablets, leveraging higher TDP silicon in a tablet form factor. The gap between the TDP of Apple’s A7 and those two SoCs isn’t huge, but there is a gap. I only include those platforms as a reference point. As you’re about to see, the work that Apple has put into the A7 makes the iPhone 5S performance competitive with both. In many cases the A7 delivers better performance than one or both of them.

In September of 2013, the world’s preeminent independent processor expert compared Apple’s latest iPhone chip with Intel’s fastest tablet chip and concluded that the two perform similarly — even though the Intel chip draws more power, contains four cores versus the A7’s two, and is produced with a more advanced manufacturing technique. If Apple’s chip design team can create a phone processor that performs on par with Intel’s fastest tablet chip, the company’s “highest priority”, then there’s no reason to believe that the same team at Apple can’t design chips powerful enough for any Mac in the company’s lineup.

Apple has already released a line of A-series chips tailored specifically for iOS devices, and the company is most definitely working on a line of B-series chips tailored specifically for Macs. When that B-series chip — or set of B-series chips that runs in parallel — is ready, Apple will be able to switch to ARM-based Macs without sacrificing user experience. On the contrary, because the company is no doubt designing its line of B-series chips in tandem with Mac OS X, there would be iPhone-like hardware-software optimization, improving user experience.

Apple Would Make More Money Per Mac And Sell More Macs

Going from chip concept to manufactured product can be broken down into two separate and distinct steps. The first is chip design — figuring out what features the processor will have and how it will work. The second is manufacturing — turning a file that exists on a screen into a physical product you can hold in your hand.

Today, Intel designs the chips in Macs and manufactures them, profiting on both of those steps. But if Apple swapped out Intel’s chips for its own ARM-based designs, an external company would profit on only one step of the chip creation process, not both, leading to a decrease in the cost of building a Mac. By my conservative estimate, Apple would be able to drop the price of the base model 11- and 13″ MacBook Airs by $50 and still make more profit per unit on each than it currently does.

This cost savings would apply to the entire Mac lineup. Apple would be able to drop prices across the board and make more money per Mac than it does today — and with lower prices, the company would sell more of them, too.

Apple Would Be Able To Create Better Macs

When Apple announced the iPhone 5S, it explained that all of the fingerprint data associated with Touch ID “is encrypted and stored inside the secure enclave in our new A7 chip” where it’s “locked away from everything else”.

Apple wouldn’t have been able to create Touch ID if the iPhone were powered by an Intel chip instead of an Apple-designed one. There wouldn’t have been a “secure enclave” on the iPhone’s processor to store the fingerprint data, nor would there have been perfect hardware-software integration. Apple was able to implement Touch ID because it designed the A7 chip in tandem with the iPhone 5S’s software and the rest of its hardware.

I’d bet that there are features Apple envisions for the Mac that simply can’t be built while Intel designs the chips inside of them. To implement those ideas, Apple would need to switch the Mac to ARM-based processors, because only then would the company have the ability to design chips customized for specific features. If Apple moved the Mac to ARM-based chips, the company would literally be able to create better products than it can today.

This brings me to something else Steve Jobs said when he announced the transition from PowerPC to Intel. Ultimately, he explained, Apple switched for one simple reason: “We can envision some amazing products we want to build for you, and we don’t know how to build them with the future PowerPC roadmap.”

The same logic applies today. It’s not a stretch to imagine Tim Cook walking out on stage and saying, “We can envision some amazing products we want to build for you, and we don’t know how to build them with Intel’s chips.”

As I first said more than three years ago: ARM-based Macs are definitely coming.