This could help them make inroads to people who might not have considered a home console before due to their relatively large size. Wouldn’t be surprised if the Switch did well with this market and now MS wants a slice of that pie.
I am not expert, but I cannot remember ever hearing that before. Why would arm have better absolute performance than x86?
As a spectator, reading tech press about architectures gave me the impression that even in performance per watt, the advantage arm has over x86 is fairly small, just that arm chip makers have always focused on optimizing for low power performance for phones.
Better general design, or easier to include more cache. All the normal reasons one architecture might perform better than another. I mean, you heard about Apple switching all their processors to ARM, right?
> As a spectator, reading tech press about architectures gave me the impression that even in performance per watt, the advantage arm has over x86 is fairly small, just that arm chip makers have always focused on optimizing for low power performance for phones.
Intel would certainly like you to believe that. But for all their talk of good low-power x86s being possible, no-one's ever actually managed to make one.
Apple's decision to switch to ARM had many reasons, licensing being just as important as performance, perhaps more so.
The low power variants of Zen are very efficient. You're still looking at Intel, but they've been leapfrogged by AMD on most fronts over the past half decade (still not market share, but Intel still has their fabrication advantage).
Intel tried and ran into most of those same problems. Their Atom-based SoCs were pretty competitive with ARM chips of the day, it was the reliance on an external modem, friction with x86 on Android and a brutally competitive landscape that resulted in their failure.
Regardless of architectural advantages from one vendor or another, the point remains that the arguable preeminent expert in CPU architecture believes that ISA makes little difference and given their employment history it's hard to make the argument of bias.
The way I remember it the performance and battery life never quite lived up to what they said it would.
> Regardless of architectural advantages from one vendor or another, the point remains that the arguable preeminent expert in CPU architecture believes that ISA makes little difference and given their employment history it's hard to make the argument of bias.
Current employer is a much heavier influence than prior employers, and someone who's moved around and designed for multiple ISAs and presumably likes doing so has a vested interest in claiming that any ISA can be used for any use case.
There's a long history of people claiming architecture X can be used effectively for purpose Y and then failing to actually deliver that. So I'm sticking to "I'll believe it when I'll see it".
Maybe apple could have stayed with x86 from AMD with some sort of co-design, but apple likely preferred to design their own chip so they would control the whole process and keep more of the profits. Designing their own chip also seems like it allowed apple to leverage their investments in TSMC for making their phone chips to also include their laptop chips. I wonder whether they already had a long term plan to dump Intel, or whether the plan started as a reaction to the serious problems that began developing at Intel years ago.
There's also Xtensa cores (audio coprocessor) and ARM cores included (PSP, Pluton, and I think there's extra ARM coprocessor for handling some sensor stuff optionally)
AMD uses ARM for its PSP as well which is more than just a TPM.
But afaik it also matters what type of license AMD has.
AMD would be need an ARM architecture license (like Apple has). This license allows you to do whatever you want with the chip (such as adding a x86 style memory model).
The downside to the architecture license is you have clean room design the chip entirely.
The fTPM does indeed run on the PSP, so on the ARM cores, among many other things like DRAM training.
Sticking with AMD for GPUs makes sense no matter the CPU architecture. AMD is competitive on x86, and at the moment Samsung is working out the kinks to integrate Radeon GPUs with their ARM CPUs... so once Samsung has proven the concept works (and, of course, paid for the effort), maybe large consoles will make the switch.
It shouldn't be much of a problem for game studios in the end, most games run on one of the household-name engines anyway and they have supported ARM for many years for mobile games.
Which instructions?
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.
If you want to be more lenient, the $129 Apple TV has A15 which is ~same design, but with less cores.