[cestith]

Apple wouldn't have used ARM for the iPhone and iPad if the cores hadn't been proven in other similar platforms. ARM goes back a long time. My Psion palmtops have ARM cores. Many of the WinCE systems have ARM cores. The ARM processors in fact go back to 1985, with the ARM Development System for the BBC Micro and then the Archimedes in 1987.

There's a whole world of ARM processors out there. The ISA, packaging, software, and expertise around it everywhere in the world helps make that ecosystem stronger. Before ARM there was Intel, and before Intel was PowerPC, yet even before that there were the 68000 series Macs. And before the Mac, there were the 65816 in the IIgs and the 6502 in the Apple II. Don't be surprised if Apple is an early adopter of RISC-V for support processors. If they decide they've made them performant enough after a few years of that, don't be surprised if they use them as CPUs and stop needing to license cores and ISAs from ARM at all.

But I can promise you one thing. Apple didn't look at the 18 MHz v7 cores from Cirrus Logic in the Psion Series 5 and immediately decide they could make a mainstream desktop CPU out of it. The competition of companies like Samsung, Qualcomm, and Broadcom in consumer electronics has a lot to do with how ARM cores became suitable for Macbook.

[klelatti]

The bit you’ve missed out here is that the ARM64 ISA is very different to earlier Arm ISAs and that Apple almost certainly was deeply involved in its development and was first with a production core.

Given that and in the absence of a clear rationale I find it hard to see why Apple would want to to incur the costs of a move to an ISA it’s had no influence over - certainly not to save an immaterial licensing fee.

[brucehoult]

At the very first moment that there was a company called "ARM", in 1991, Apple owned 1/3 of it, the other partners being Acorn(who invented it) and VLSI Technology (who made the chips).

Psion adopted a CPU Apple was using in, AND A COMPANY THEY OWNED developed for, the Newton and eMate, not the other way around. The ARM710 used in the Series 5 was the same as Apple used in the eMate.

[cestith]

Since that time, there was a point Apple was nearly bankrupt. Also since then they partnered on another new processor technology and put that one in the Mac. Then they got rid of that one and went to Intel chips. Only recently did they develop an ARM core they considered superior to the desktop competition. The whole Newton/eMate line were nice but were marketplace flops.

Apple plays a long game, but saying they funded ARM in the mid 1980s so they could slowly grow those cores by themselves for themselves in 2020 and later ignores a whole lot of history about both Apple and ARM.

[klelatti]

The long arc of history is towards performance per watt.

Apple knew that when it invested in Arm and chose Arm for Newton, for the iPod and the iPhone (note Apple has been selling Arm based products continuously since 1993 apart from 1998-2001).

It’s no accident that there is an Arm based CPU in the Mac now. Apple’s most important Mac is the MacBook and performance per watt is key. Until someone can offer an architecture that demonstrably does much better on this metric Apple will stick with Arm.

[cestith]

The performance per watt point is a more than fair argument. It also cuts both ways. If Apple decides ARM is still the performance per watt leader in 20 years, there's a good chance they'll still be using it. If any other processor tech reaches a better spot, they have the expertise and the semi-closed ecosystem to switch processors quicker than pretty much anyone else in most of the spaces into which they sell. It's something they've not only done multiple times, but done well and are known for doing well.

[klelatti]

100%. Look what happened with GPUs and Imagination. Personally I think CPUs and ISA will become less important as more functions are passed to special purpose engines. Perhaps RISC-V extensions might be a trigger but I suspect Arm will offer Apple whatever they want to keep them (both on the ability to add new extensions and on price - if they are paying anything at all at the moment!)

[Someone]

> Apple didn't look at the 18 MHz v7 cores from Cirrus Logic in the Psion Series 5 and immediately decide they could make a mainstream desktop CPU out of it.

It’s more likely that Psion looked at the 20 MHz ARM cores that Apple shipped in the Newton and decided they could make a Psion with that.