Chester (lamchester.delete@this.gmail.com) on November 21, 2020 2:49 pm wrote:
> juanrga (no.delete@this.no.no) on November 21, 2020 9:22 am wrote:
> > Adrian (a.delete@this.acm.org) on November 21, 2020 7:14 am wrote:
> > >
> > >
> > > At TechSpot, they have run a set of benchmarks on all Zen generations
> > > (1, 1+, 2, 3) and Comet Lake (i.e. Skylake microarchitecture).
> > >
> > >
> > > What is interesting is that, as much as possible, the only differences
> > > in the 5 systems were in the core microarchitecture.
> > >
> > >
> > > The clock frequency was fixed at 4 GHz for all systems, all had 8-core CPUs,
> > > all had the same memory modules, the same coolers, the same GPUs.
> > >
> > > Therefore these show the evolution of the IPC, as well as this is possible.
>
> Some interesting things:
> - Zen 3 beats Intel on full random mem access latency despite using
> a separate IO die. Maybe 6 page walkers are playing a role.
> - Zen 2 and Skylake swap places on some stuff, with SKL mostly winning in gaming and Zen 2 taking
> most of the rendering/compression/content creation tests. This might have to do with games having
> a huge memory footprint with bad access patterns, where SKL's lower memory latency helps. Zen
> 3 may make up for this with 6 page walkers and much more cache accessible per-thread.
>
> > >
> > > (Until the launch of Rocket Lake, there are no newer Intel
> > > CPUs that could be compared in identical conditions.)
> > >
> > >
> > > https://www.techspot.com/article/2143-ryzen-5000-ipc-performance/
> > >
> >
> > They are testing some overclocked chips, not getting IPC on stock settings,
>
> You can see perf at stock setting in regular reviews.

Most regular reviews tested Zen on non-stock settings. But what is relevant to this thread is the above IPC comparison isn't measuring stock IPCs.

> > and
> > the choice of applications is too narrow: rendering, rendering, rendering,...
>
> Try scrolling down a bit. The little bar on the right of your browser window can do that - try dragging
> it down or pushing the down arrow at the bottom, and you'll see a whole lot more than rendering.
>
> There's compression, gaming, video editing, image editing, as well as a couple
> of synthetics.

The author of the review differentiates between "games" and "applications"; it would be a bit weird if I add gaming when discussing his applications results. Yes, there is compression, this was included in the ellipsis that I wrote above.

> Not the most complete coverage, but miles better than SPEC.

Whatever you say, but the review is rather irrelevant to get the average IPC, because it is comparing stock vs non-stock, using a very narrow choice of application workloads and not providing full CPU tests in the gaming measurements.