RE: [Cerowrt-devel] risc-v options?

[Arun Ray Ramadorai <ray@ramadorai.org>]

Architecturally I would say it is still about 8yrs behind ARM. Cache performance, power management, and virtualization in particular are not mature yet and need consistent investment of time and dollars to get RISC-V to the same level. That having been said I do see a lot of companies looking at it as way to reduce their licensing costs. I think the motivation of the community should be to encourage corporate investment with the expectation that the resulting development is made available to everyone. 

Ray

-----Original Message-----
From: Cerowrt-devel <cerowrt-devel-bounces@lists.bufferbloat.net> On Behalf Of Dave Taht
Sent: Tuesday, November 30, 2021 8:51 PM
To: David P. Reed <dpreed@deepplum.com>
Cc: cerowrt-devel <cerowrt-devel@lists.bufferbloat.net>
Subject: Re: [Cerowrt-devel] risc-v options?

and pspn looked interesting at 400Gbit: https://arxiv.org/pdf/2010.03536.pdf

On Tue, Nov 30, 2021 at 4:33 PM Dave Taht <dave.taht@gmail.com> wrote:
>
> also, a 2.5ghz, 16 core chip was open sourced last month.
>
> https://www.cnx-software.com/2021/10/20/alibaba-open-source-risc-v-cor
> es-xuantie-e902-e906-c906-and-c910/
>
> On Tue, Nov 30, 2021 at 4:23 PM Dave Taht <dave.taht@gmail.com> wrote:
> >
> > On Tue, Nov 30, 2021 at 2:52 PM David P. Reed <dpreed@deepplum.com> wrote:
> > >
> > > For what?
> >
> > Because it's shiny. Because I don't care for the owner of softbank 
> > and arm very much. Because at least the core is open source, and I'd 
> > really like to try out some long held ideas about reducing context 
> > switch latency. And there's a couple instructions I'd like to add.
> >
> > >I have recently gotten a MicroSemi RISC-V SoC board with embedded FPGA (or maybe it is better thought of as an FPGA board with multicore hard logic RISC-V host.) Runs Linux very fast. It's not set up to be a router, though - not unless I populate its PCIe  slot with NICs. Standard Linux drivers for PCIe devices all work quite well, so far.
> >
> > how fast can it context switch? (irtt bench)
> >
> > I am impressed that it works with anything on pcie.
> >
> > I was mostly dismissing risc-v as a toy that could never catch up to 
> > arm 3 years ago, but with the enormous chinese investment in it...
> >
> > >
> > >
> > > These early 64 bit RISC-V implementations are pretty darn good, but unlike Intel's Xeons, they don't yet handle memory channel performance very well.
> >
> > Intel has always had an advantage in on-chip cache.
> >
> > >
> > >
> > >
> > > (The 32-bit RISC-V's are really competing with ARM based microcontrollers for embedded systems. I don't find them interesting, though I have a couple sample boards with 32 bit RISC-V cores).
> >
> > I don't find 32 bit risc-v interesting. I did fiddle with the 128 
> > bit risc-v stuff for a while.
> >
> > >
> > >
> > > A random guess on my part: even consumer routers will be moving to 64-bit processor designs in the next couple years.
> >
> > Many already have.
> >
> > > That's because the price difference is getting quite small, as a percentage of total product cost, and because it is hard to buy "small memory address space" DIMMs. I could be wrong, but extrapolation from today's trends suggests that is more likely than not.
> >
> > 802.11ax standards require - no joke - a 2MByte buffer per station.
> >
> > >
> > >
> > >
> > >
> > >
> > > On Friday, November 26, 2021 3:02pm, "Dave Taht" <dave.taht@gmail.com> said:
> > >
> > > > has anyone tried the latest generations of risc-v?
> > > >
> > > > https://linuxgizmos.com/17-sbc-runs-linux-on-allwinner-d1-risc-v
> > > > -soc/
> > > >
> > > > --
> > > > I tried to build a better future, a few times:
> > > > https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
> > > >
> > > > Dave Täht CEO, TekLibre, LLC
> > > > _______________________________________________
> > > > Cerowrt-devel mailing list
> > > > Cerowrt-devel@lists.bufferbloat.net
> > > > https://lists.bufferbloat.net/listinfo/cerowrt-devel
> > > >
> >
> >
> >
> > --
> > I tried to build a better future, a few times:
> > https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
> >
> > Dave Täht CEO, TekLibre, LLC
>
>
>
> --
> I tried to build a better future, a few times:
> https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
>
> Dave Täht CEO, TekLibre, LLC



--
I tried to build a better future, a few times:
https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org

Dave Täht CEO, TekLibre, LLC
_______________________________________________
Cerowrt-devel mailing list
Cerowrt-devel@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/cerowrt-devel