According to a report form Bloomberg News, Apple is considering switching away from the Intel chips that have been powering Mac computers for years, in favor of chips designed in-house, like the A6 and A6X powering the new iPhone 5 and iPad 4.
Apple's shown a renewed interest in chip building recently. In September, it was confirmed that the A6 chip in the iPhone 5 was a custom core designed by Apple using ARM's reference designs. In the past, Apple had just tinkered here and there with pre-designed cores on its chips, like the Cortex A9 or A15. It was a huge step for Apple. The chip improved both power efficiency and and improved performance, and the A6X which came just a few weeks later, improved graphical performance as well.
The talk escalated when Apple hired top chip designer Jim Mergard away from Samsung. Mergard had spent 16 years with AMD before that, and was working on Samsung's growing interest in designing its own Exynos chips. That was followed pretty quickly and predictably by reports that Apple was trying to wean itself off of Samsung's chip manufacturing services. Good thing, then, that back in 2010 it bought up a company called Intrinsity that makes ARM processors.
And just a week or so ago, Bob Mansfield returned to the company to consolidate all wireless and semiconductor development into one big Technologies division. Mansfield, according to Bloomberg's sources, has been interested in unifying the iOS and OS X experiences for some time now—more so than deposed iOS honcho Scott Forstall. A move to Apple-developed chips across all of its devices would probably be necessary to make that happen on a meaningful level.
Since Apple switched to Intel chipsets in 2006 (the switch was announced in 2005), with the Core Duo in the new iMac, Apple has run its machines with standard Intel chips, from the Core 2 Duo on the the newer Core generations. And aside from a few hiccups, like when Nvidia, an Apple partner, couldn't make compatible chips for Intel's Core series because of a licensing nightmare, things have been pretty great for both parties since then.
However, Intel has struggled to make a dent in the mobile chipmaking, with its Medfield chips not delivering the efficiency needed for the smaller devices. That, combined with recent news that ARM isn't just developing a 64-bit chip, but also a full version of Windows 8 to run on it, highlight how serious ARM is as an Intel competitor.
ARM chips in Macs is not a new rumor. It's been floated out before. But the difference is, Apple's building its own cores now (based on ARM's reference designs, but still, Apple-owned).
So why did it never happen, and why is it such a big undertaking for Apple if it does decide to switch? A few reasons, but really, mainly, just this: Performance. John Brownlee at Cult of Mac had an exhaustive piece earlier this year about why ARM wasn't going to make it into Macs over Intel. The main reason was that the performance of ARM's chips simply cannot keep up to Intel's modern offerings. Like, not close. (The other reason is how extensive the migration process for OS X would have to be, along with all the apps, in the Mac App Store and elsewhere. The bellyaching when PowerPC app support was finally dropped with Lion in 2011 was already sort of loud, before you get into a second move in 10 years.)
The newly announced Cortex A50 series changes that some. And Apple having its hands in that mix changes the calculus some too. But it's worth a quick look at the landscape to realize just how big a move this would be for Apple, and how confident Apple must be in its ability to get it done if it's seriously considering it.