hobold (hobold.delete@this.vectorizer.org) on October 10, 2020 8:58 am wrote:
> Blue (blue.delete@this.blue.com) on October 8, 2020 9:58 am wrote:
> [...]
> > If AMD can keep up this 15-19% gains every generation, when do
> > the "big on ARM" folks think ARM will effectively catch up?
>
> Most of Zen3's gains seem to come from the reduction of latency (to memory, and between cores). In a sense,
> Zen3 shows how good the Zen2 core already was, if it hadn't been starved for data. The lowered base clocks
> of Zen3 also point to a higher utilization of core execution units (and thus more power draw) at 100% load.
> This seems to be more evidence for there being fewer pipeline bubbles in Zen3 compared to Zen2.
>
> But one cannot reduce latency below zero (no matter what marketing departments
> say), so these gains are not very likely to be repeated by AMD.

Yes you can :-) Value prediction is real, and done competently provides genuine speedups...
As far as I can tell no-one is doing value prediction yet (as always asterisk against Apple...) but it's still a promising technology once everything easier has been done.

> On the flip side, SMT gains appear to be lower in Zen3, because a single thread
> alone can now utilize more of the core execution units than it can in Zen2.
>
>
> It's not ARM that needs to catch up; it's Intel.