Adrian (a.delete@this.acm.org) on October 10, 2020 1:59 am wrote:
> Mr. Camel (no.thanks.delete@this.gmail.com) on October 9, 2020 6:30 pm wrote:
> > Blue (blue.delete@this.blue.com) on October 8, 2020 9:58 am wrote:
> > > AMD's announce Zen3 with an average of 19% IPC uplift "in desktop applications"
> > > and about a 5-10% clockspeed boost (ST, MT unknown).
> > >
> > > Seems like they're rightfully pushing to up their margin.
> > >
> > > If AMD can keep up this 15-19% gains every generation, when do
> > > the "big on ARM" folks think ARM will effectively catch up?
> >
> > How would an 8 core Zen 3 desktop chip compare to a desktop class 8 core Willow Cove chip?
> >
> > This assumes that a desktop Willow Cove could hit higher frequencies
> > than the mobile version due to more thermal headroom.
> >
> >
>
> The single-thread Cinebench showed Zen 3 @ 4.8 GHz as faster
> by 6% than Willow Cove (Tiger Lake) at the same 4.8 GHz.
>
> So Rocket Lake (it is not known whether its Cypress Cove core is more similar to Willow
> Cove or to its predecessor from Ice Lake, but the differences between these 2 cores are
> small anyway) will have to reach at least 5.3 GHz to slightly exceed a 4.9 GHz Zen 3.
>
>
> For multi-threaded applications an 8-core Rocket Lake will be limited to a lower base frequency than Comet
> Lake (because of doing more work per clock cycle) and it is unlikely that it would match even a 12-core
> Zen 2, and certainly it will be easily beaten by an 8-core Zen 3, due to its higher energy efficiency leading
> to higher clock frequencies when limited by the TDP. The low efficiency of Rocket Lake for power-limited
> MT tasks will be mitigated by 125 W vs. 105 W, but compared to Zen 3 this will not be enough.
>
>
>
>
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Sorry, I might have misinterpreted your question, because the only "Willow Cove" like desktop CPU announced on Intel's roadmaps is the 14-nm Rocket Lake with Cypress Cove.


If your question was about a *10-nm* Intel desktop CPU, i.e. a desktop version of the Tiger Lake H, expected to be launched next year with a TDP up to 65 W, then the answer is different.

Tiger Lake H is expected in laptops, but it might also show up in small desktops, e.g. in a successor of the Intel NUC Pro model that currently uses a Coffee Lake Refresh H 8-core CPU.


Tiger Lake and Zen 3 should have similar energy efficiencies, so they should be close in multi-threaded benchmarks at the same number of cores.

We do not know yet whether an 8-core Tiger Lake will beat an 8-core Zen 3 in MT benchmarks or vice versa, but they should not differ much anyway.

Of course, 12-core and 16-core AMD CPUs will be much faster.


However, despite the higher TDP, I do not believe that a desktop Tiger Lake H may have a much higher turbo than the current 4.8 GHz of Tiger Lake U.

The 4.8 GHz seems to be a limit due to the process, like the 4.9 GHz of the Zen 3 and the active core at that frequency consumes much less than allowed by the thermal headroom.

Until March 2021, Intel might tweak a little their process and their masks, so I expect a top speed of either 4.9 GHz or at most 5.0 GHz for Tiger Lake H, which will have thus frequency parity with Zen 3, but Zen 3 appears to have a better IPC in ST tasks.