[xoa]

>They will probably need a Rosetta equivalent to emulate x86 for all the applications that are slow to switch.

Well, and all the applications that won't switch. Also even on the Mac virtualization/containerization is not nothing. The Mac is a different market and use profile then iOS, and while Apple based on past history won't support an old arch indefinitely neither are they likely to completely blow off backwards compatibility. Compared to previous transitions dropping x86 would have extra complexities as well, so previous experience may not be entirely applicable. In particular Apple would be moving away from the full fat computer standard rather then no change or towards one, which may change the payoff for users despite Apple being much bigger. The absolute performance differences (immediate and future) also aren't likely to be as big.

I don't want to underestimate them, and huge disruption is inevitably coming down the pipe anyway and Arm may well emerge a winner there regardless, but it's also just a really big challenge.

>That might be tricky because of the huge surface area of the x86 instruction set.

Transmeta was able to do a decent job, and I think Novafora is still around and licensing their IP? Granted a lot of instructions have been added since then, but Apple certainly has a lot of expertise there as well and a great deal of capital to aim at the issue.

[justinator]

Apple's track record of being able to switch architectures is absolutely incredible. If they want to switch, they can switch.

To think that deep in the Apple labs that don't already have A-X laptops running - and have for, for a while is not thinking like Apple would.

[gsnedders]

> To think that deep in the Apple labs that don't already have A-X laptops running - and have for, for a while is not thinking like Apple would.

Right. To me it's unthinkable given the amount of low-level code shared between iOS and macOS that macOS hasn't been running on ARM since day 1 of iOS.

[yjftsjthsd-h]

Yeah; if nothing else, the first versions would have been "port Darwin to this SoC". Maybe they never ported the GUI components, but it would be unsurprising if they did.

[xoa]

>Apple's track record of being able to switch architectures is absolutely incredible. If they want to switch, they can switch.

Sure, but don't discount how every specific instance can be a bit different either. As I said they've got expertise, they've got capital, and there are even previous paths to follow here. But at the same time every time has its own unique hurdles. Previously with 68k -> PPC and then PPC -> x86 for example they were going to something that was not merely just an improvement in some important respect right off but also had a clear long very steep growth ramp ahead thanks to fabrication improvements if nothing else. In the PC world we were still very much in either a very steep or at least steeper part of the S-curve. But those days are just plain done, the issues presented by physics and the geometry sizes being worked with now are simply fundamentally harder. There is certainly more room for improvement year to year for a long while, and more chances to grow horizontally with valuable new features, but it's not like a system made now will be obsolete in 3 years either.

Additionally those were coming at points in Apple's life with a dramatically smaller installed base, and they were also going away from something more proprietary (at least in principle, obviously CHRP never actually worked out that well). The move to x86 which brought Macs in line with everything else meant a huge amount of software opened up to more trivial porting, huge amounts more opened up to trivial virtualization, a vast 3rd party hardware market became more easily accessible, etc. That definitely helped offset some of the old Mac software that ultimately didn't make it, even more so because due to above it is still quite possible to run old Mac software fine: Classic can be emulated, and 10.6 can be run under virtualization still which in turn grants access to Rosetta even on new Macs, and the absolute performance advantages vs 12+ year old systems are significant enough that even with the overhead it's still fine.

Basically there are a lot of subtle day-to-day advantages that come from everything running the same instruction set underneath, or at least being able to stick some sort of translation layer in there. Again, absolutely not saying it's something Apple can't tackle, just that it's a big challenge and I think it's bigger now then it was any time previously. Of course, Apple too is bigger now then any time previously! They're not infallible though and I hope they get the balance right here.