The iPad Pro's M4 chip breaks the rules and changes everything about Apple silicon

Now that the M4 iPad Pro is here, what will this mean for the chips coming to the iPhone and Mac?

- JASON SNELL

Well, that was fast. The M3 chip (fave.co/3MZyVey), introduced last October, is already yesterday's news (fave.co/4dOpmen). We're living in an M4 world, courtesy of the surprising announcement that the new iPad Pro (fave.co/3UW5UUi) is powered by Apple's next generation of chips (fave.co/450PKXK).

Even if you don't care about iPads, this announcement will affect the trajectory of the Mac and iPhone in quite a few ways.

The first question to answer is: Why so soon? The iPhone gets a new chip generation once a year when the new iPhones arrive. Apple likely wants the M series on a similar cadence, since the two chips are really variations of one another. The rush to the M4 breaks this cycle.

A NEW CHIP ARCHITECTURE

The answer is complicated and has a lot to do with the vagaries of chip manufacturing (fave.co/3wNOZNO). To simplify: TSMC, Apple's chipmaker, introduced a new 3-nanometer process last year, which enabled Apple to ship the M3 (and A17 Pro) chips and boast that they were the first major chips to be on a 3nm process.

The problem is that, even then, the manufacturing process that built those chips was a dead end. TSMC was recalibrating its chip manufacturing and moved from its old N3 technology to the new (and very different) N3E version. The new version is not compatible with the previous method of designing chips, which mandated a wholesale redesign. When Apple says that the M4 is made using a second-generation 3nm chip technology, this is what it's talking about.

Basically, Apple used the M3 generation to get to 3nm before everyone else, but it knew that it would need a new design for the system TSMC was building toward. Hence the M4-and presumably the A18-were redesigns Apple absolutely had to do.