They did, but to get it running as well as they did they had to deviate from generic ARM by adding support for the x86 memory model in hardware. Apple was in a position to do that since they design their own ARM cores anyway, but the off-the-shelf ARM reference designs that most other players are relying on don't have that capability.

You can do it with standard ARM instructions these days.

I vouched for this comment, but it looks like you're shadow banned. You might want to email support.

> these days

Which instructions?

Those that are part of FEAT_LRCPC.

> They did, but to get it running as well as they did they had to deviate from generic ARM by adding support for the x86 memory model in hardware.

Note that this is actually very cheap in hardware. All ARM CPUs already support memory accesses that behave similarly to x86. It's just that they're special instructions meant for atomics. Most load and store instructions in Aarch64 don't have such variants, because it'd use a lot of instruction encoding space. The TSO bit in Apple's CPUs is really more of an encoding trick, to allow having a large number of "atomic" memory instructions without needing to actually add lots of new instructions.

They haven't demonstrated it at console-level prices.

If you wanna play semantics, and argue that the demonstration requires a M-Something chip, then they have in a $599 iPad Air with M1. Or I guess a Mac Mini with M2 for the same price.

If you want to be more lenient, the $129 Apple TV has A15 which is ~same design, but with less cores.