Apple switch from Intel chips? The real question may be when, not if

Once again there’s a rumor about Apple exploring plans to dump Intel(s intc) chips on its Macbook line of computers. The rumor is a favorite, but the question is probably less a matter of whether or not Apple (s aapl) is weighing a switch and more about when such a switch would happen. From a chip point of view, the stars are lining up, but they aren’t in formation just yet.

The combination of the overall change in computing, from something that occurs at a desk to something that happens on a variety of devices throughout the day, and higher performance chips based on the ARM(s armh) architecture planned for next year are probably the spur for the latest rumors. The change in computing has been happening for some time, but only last week did ARM announce its next generation processor cores, the A-53 and the A-57. The big focus of those cores was that they can support 64-bit computing — a necessity for servers and the personal computer markets today.

Better chips mean a better experience

In a conversation last week with Nole Hurley, VP of marketing and strategy for ARM’s processor division, we briefly discussed the likelihood of one of ARM’s new A-50 cores having the chops to make it into laptops and other devices dominated by CPUs. The 64-bit compatibility associated with the next generation ARMv8 architecture means that the cores will be able to address more memory. That gives devices the ability to support having scores of open tabs on their browsers while running a dozen different programs or apps.

Until these cores were announced, ARM cores have supported 32-bit processing. That’s fine for mobile devices where ARM has dominated, but when it comes to content creation, 64-bit compatibility is crucial, as you can see from my colleague Kevin Tofel’s review of a Chromebook running on an ARM chip versus one running an Intel chip. Thus, with these new cores, ARM has a product that could possibly compete in the laptop and personal computing market. Those cores will be out next year with devices running that IP expected in 2014.

If Apple is contemplating this switch it is because it realizes that now that computing has gone mobile, the x86 architecture, which was optimized for performance at all costs, has been superseded by the ARM instruction set that optimizes energy efficiency at all costs. The difference now is that ARM has also been boosting performance while optimizing for efficiency and has reached a level of performance parity that supports today’s application needs. Intel’s focus on efficiency in x86 is kind of like retrofitting a Ferrari to be more fuel-efficient while ARM has been building a Tesla.

Apple hasn’t stood still however waiting for better ARM cores. It has built a better core using its ARM architecture license to tweak the current generation ARMv7 instruction set to increase the performance of the A6 processor in the iPhone 5. (An architecture license lets Apple tweak the core designs that ARM builds.) As this deep dive from Anand Tech illustrates, Apple has already made a processor for phones that could rival a traditional CPU.

Apple hasn’t forgotten about the need for software

And Apple may have already started down the path of optimizing its OS X Mac operating system for the ARM-based architecture, one major step it needs to take before any transition off Intel’s x86 platform. Back in 2007 Apple said the iPhone runs OS X and Apple later clarified that it runs on the same kernel software. Thus, must of the optimization needed to fully retrofit OS X for the ARM instruction set may already be done. That only leaves the popular software running on the MacBook left for a retrofit, and because Apple already has adapted popular programs of its own such as iMovie and iPhoto for iOS, that work may also be done.

The biggest holdout is probably Microsoft Office, and one would assume that Microsoft(s msft), once it got word of Apple’s plans it would act to preserve that software on the popular Macbook platform. However, Microsoft has been dragging its feet with ARM. For example it supports Windows RT and has a mobile platform that runs on ARM chips, but Windows 8 still doesn’t.

So, as the rumor mill works over the possibility of an Apple switch from Intel to ARM-based chips in the Macbook, it’s worth noting that the hardware is almost in place and the software is probably mostly there. The biggest unknown in this plan is how Intel might react to the threat of an Apple defection.