Doug S (foo.delete@this.bar.bar) on September 24, 2021 2:12 pm wrote:
> dmcq (dmcq.delete@this.fano.co.uk) on September 24, 2021 1:05 pm wrote:
> > SVE is in multiples of 128 bits so not so bad! I' guess
> > the first hetrogenous system with a size greater than
> > 128 bits will be an Apple one and I guess they'l go for having the same size in both, perhaps they'll share
> > an SVE unit amongst the small cores like ARM. But they haven't even announced a system with SVE yet.
>
>
> Considering Apple was able to ship millions of ARMv8 CPUs less than a year after ARM released the
> spec (a FAR more difficult accomplishment than adding SVE) if Apple was going to ship CPUs with SVE
> they probably would have. SVE was announced as an optional extension to ARMv8.2 over five years ago,
> and SVE2 over two years ago - they also submitted patches for SVE2 to LLVM in late 2019.
>
> Now it is possible that the ARM Mac effort with M1 and soon Jade-C took up too much engineering
> bandwidth and they put SVE2 on the back burner, but if they were planning on introducing
> it at all doing so with the very first ARM Macs (i.e. making that something developers
> could assume exist in every ARM Mac) would be the most logical course.

Not necessarily.
Until now Apple has debuted new cores with iPhones; so inertia made people believe this would always be the case. But nothing says it has to be this way!

Going forward a more logical pattern would be
- new cores introduced via a Mac high-end product, which is a more logical place to ooh and ahh over all the new whatsits and thingamajigs that have been added to make this core X% faster than its predecessor.

- two year cadence on cores. This allows for deeper changes, and doesn't have to mean two year cadence on SoC's, as we saw this year with, essentially, last year's core but improved GPU, NPU, SLC and who knows what else.

- this scheme also allows more flexibility in timing. Everyone expects iPhones in September; it will be tough to break that. But high end Macs arrive when they arrive. The schedule can plan for the core to be ready in January, but if it slips two months that won't be a catastrophe.

- Apple already have a scheme of multiple cores and SoCs of different ages across different products. Expanding this from the current scheme of two SoC "levels" (good, A#; and better M#) to three including a best level (new random letter#), and having a given year's products spread over these three SoCs and two or three cores is no serious change (look at either iPhones, or at iPads, right now using M1, A15, and A13)

In other words, I'm not yet convinced that the A15 represents any sort of intrinsic slow-down in core design, more that it's just the first SoC of Apple's Phase 3, and like any such transition it's hard to see the pattern with only one example. I'd say let's wait for the high end machines before getting excited. (And high-end means high-end. I expect the same pattern of a minor upgrade to the M1 -- pick up the new GPUs, perhaps get either more RAM or LPDDR5 -- but essentially the A15 core. I'm referring to the iMac Pro/Mac Pro class machines.)