More Mac on ARM Speculation

August 5th, 2014

There’s no dispute that the lack of serious Mac refreshes this year can be blamed on Intel. The new Broadwell chip family, using 14 nanometer dies, is late to the party. The chips that Apple requires for Macs aren’t available yet, and that may push those refreshes off to 2015. So to make do, Apple is using slightly faster chips from the previous generation, Haswell, to convey the impression of a speed bump. The combination of slightly lower prices and slightly better performance makes the recent MacBook Air and MacBook Pro with Retina display upgrades pretty good values overall.

Clearly customers approve, since Mac sales growth continues to outpace the industry.

Now the last time a chip manufacturer didn’t deliver the goods to Apple, a wholesale processor switch followed. That happened in 2005, when the PowerPC G5 stagnated, with no note-book version in sight. Windows PCs with Intel Inside were speeding past Macs, so Apple went with Intel.

That transition was quite smooth, since Apple had been developing an Intel version of OS X for several years in case a move became necessary. So new Macs sold in far greater quantities, and it didn’t hurt that you could run Windows software at good speed via virtualization or at full speed via Boot Camp.

Since then, Apple has established their own processor design facility, and the 64-bit A7, based on the ARM architecture, has been a revelation. After misleading claims from some tech pundits that there was no need for 64-bit on a mobile platform yet, the performance of the iPhone 5s, iPad Air and iPad mini with Retina display proved otherwise.

But that’s a low-power chip designed to perform well in an environment where resource use has to be carefully managed. What if the A7 and its successors were scaled up to operate in a note-book or desktop personal computer? That the A7 was classified as a desktop class processor may be the hint that has helped fuel the Mac on ARM theory.

It goes like this: In the tradition of Steve Jobs, Apple wants to control everything, and building custom chips is only one part of the picture. Clearly that strategy has worked. So here we have Intel not being able to deliver the parts on time. What’s more, an ARM processor costs far less to build, in part because of design efficiencies and not being weighed down by the legacy x86 architecture that stagnates development of Intel’s chips, in part to stay compatible with older Windows apps and operating systems.

If an ARM processor can come close to the performance of an Intel chip — and that’s a huge if — Apple would still benefit from the lower design and fabrication costs. The prices of new Macs could be reduced by hundreds of dollars, particularly at the high end where some of those Intel i7 chips cost more than $500, each. Apple also has past experience moving to new processor platforms, so isn’t this a win for all concerned?

The theory sounds promising, but there’s a severe limitation that’s rarely mentioned. There are tens of thousands of existing Intel-based apps that would have to be translated or emulated in a new chip architecture. When Apple went to PowerPC, they had an emulator that was mostly compatible with existing apps, although performance suffered at first. A key part of the Intel migration was Rosetta, which allowed you to use PowerPC apps on an Intel-based Mac; it was discontinued with the release of OS X Lion in 2012. Apple clearly believed six years was long enough for you to upgrade or replace your legacy PowerPC apps, although that’s still not entirely true.

So if Apple goes to ARM, they would have to provide simple conversion tools or the ability to create “fat binary” apps that would work on Intel and ARM. There would also have to be some sort of virtualization capability so your Mac would still look and work the same as now, regardless of whether the app was built for Intel or ARM.

How would Apple accomplish that virtualization feat? Well, consider the new Metal architecture of iOS 8, which allows the CPU and GPU to “work together to achieve optimal performance.” Right now, Metal is designed to make games run much faster. But what if Metal could be tailored to provide Intel virtualization on an ARM-based Mac? Would that afford a level of performance that would be close to or identical to a native Intel chip?

Now I do not presume to know enough about the technology to claim that a Metal virtualization alternative is workable and would deliver competitive performance and superior compatibility. But it’s also clear that Apple doesn’t show its full deck of cards, and using Metal for gaming may only be the beginning.

Certainly harnessing the power of graphics chips to enhance computing is nothing new. Apple’s OpenCL technology is really exploited on the new Mac Pro, which contains workstation-class AMD FirePro graphics, to perform advanced 3D rendering and complex scientific calculations.

While I don’t know the future possibilities of moving Macs to ARM, I have little doubt that such Macs are currently being tested in the development labs. But it’s not just about control of the platform; it’s still Intel’s game to lose. If the Broadwell and future chip designs continue to run late, you can bet Apple won’t stand still.

Sounds promising, but an ARM switch wouldn’t be a cakewalk for Apple. Performance and virtualization will remain the key obstacles, and, despite some speculation on my part, I wouldn’t presume to guess how both issues will be resolved. It is also possible the stumbles in Intel’s current processor roadmap will soon be resolved, thus reducing the possibility of a move to ARM.

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9 Responses to “More Mac on ARM Speculation”

  1. Peter says:

    I was one of those people who was absolutely positively convinced that there was no way that Apple was going to go with Intel. Apple would be looking at Motorola’s dual-core PowerPC chips and there was another company that supposedly had dual-core PowerPC ready to be fabbed (that company was bought by Apple later on).

    So much for my prognosticating powers.

    Minor grouse: I always get grumbly when I hear about how PowerPC chips had stagnated. I like to point out that the last computer that Apple moved to Intel, the PowerMac/Mac Pro, used Intel’s latest high-end chips and was 10% faster than the, at the time, 2 year old Mac Pro.

  2. degrees_of_truth says:

    It would be interesting to see Apple bifurcate their MacBook line into ARM and Intel models, with perhaps the Airs being ARM-based, an Intel-based Air-ish MacBook, and Intel-based MacBook Pros. This is on the assumption that ARM would result in a significant price decrease and possibly significantly better battery performance.

  3. Jase says:

    This is a good article. I think it is inevitable that some Macs will soon move to Apple-designed ARM chips. The only question is the timing. I think that it will be within the next couple of years. At first the current software written for Intel processors will be supported by an emulation mode, but fairly quickly I imagine that software will be re-written to be optimized for the new ARM chips. Mac Book Air models will probably be the first to adopt ARM. Consumers will be told that if they do not want to run the old software in an emulation mode, or if they wish to continue to run Windows on Mac with a decent performance, that they should purchase a Mac Book Pro or another Mac that is intel-based. Over time, and as ARM-based chips continue to get better, all Macs save perhaps the Power Mac and perhaps a few other intel-based Mac models, will move to ARM chips of Apple design.

    By the way, I hope that you will continue to have John Martellaro on your show. I enjoy hearing about cutting edge PC technology such as Mac Book Pro-Open CL based academic and supercomputing, and coming flash memory that will be fast enough to also be used as RAM that Martellaro discussed in a previous appearance on your show.

    • @Jase, John is a friend and he will continue to appear on the show every few weeks. He has an amazing depth of knowledge about Apple and the industry that is mostly lacking in the tech media.


  4. Jase says:

    correction, I meant Mac Pro models with extremely powerful multicore processors can be used for academic computing with the aid of Open CL, not Mac Book Pro.

  5. dfs says:

    There’s a big difference between the situation now, where Intel is slow in delivering the new chips Apple needs, and the situation then, when it became crystal-clear that PowerPC processors had pretty nearly reached the end of the line. They never quite got up to the speed Motorola had promised, and even making them as fast as they went involved Apple in some engineering monstrosities. The next-to-last G5 MacPro, as I recall, had seven internal fans, and the final one had to be liquid cooled (and God help you if your cooling system sprung a leak). The G5 chip was at the end of the line, and this meant that if Apple didn’t switch to another processor mfr., the Mac was at the end of the line too. In that situation, at a time when the Mac was still Apple’s single major hardware offering, what was at stake was little less than the survival of the company. At the moment, Intel isn’t delivering the goods, a lot of people (myself incuded) are doubtless holding off replacing their old Macs until the Haswell chip comes out and, hopefully, we can have a Retina iMac. This is at most a temporary annoyance. Nobody doubts Intel’s long-term ability to deliver the goods, so there’s no need for panic in Cupertino. No similarly pressing need for dodges such as a new emulator or a new generation of “fat binary” software. And there’s an obvious reason for Apple not to get involved in making its own processors — nobody in the industry does that as well as Intel does, and it would be a long time before Apple might be able to change that, no matter how much money they threw at the project.

    • @dfs, Just FYI: The next Intel chip family is Broadwell. Haswell is used in all Macs except for the Mac mini (which uses the older ivy Bridge processor) and the Mac Pro (which uses the Xeon).


  6. Jase says:

    Gene, I am starting to reconsider my opinion that Apple is likely to begin using their own ARM chips in Macs soon. I think that they could do it, but there are real risks to this strategy, and the benefits are probably not great enough to justify devoting the resources to making the difficult switchover from Intel. Also, there is no real necessity to switch to ARM right now. Mac is gaining in market share every quarter, and Windows does not seem to be able to offer much competition to OS X in the foreseeable future. Apple is doing a really nice job of releasing frequent new versions of OS X, and it is probably in this area of continuously improving OS X on Intel that Apple should continue to devote some of their best people toward.

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