Path: ...!news.nobody.at!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups: comp.arch
Subject: Re: Computer architects leaving Intel...
Date: Thu, 29 Aug 2024 11:51:24 GMT
Organization: Institut fuer Computersprachen, Technische Universitaet Wien
Lines: 79
Message-ID: <2024Aug29.135124@mips.complang.tuwien.ac.at>
References: <VbrzO.74199$NSs5.15950@fx17.iad> <memo.20240828191727.19028q@jgd.cix.co.uk>
Injection-Date: Thu, 29 Aug 2024 15:14:40 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="2976ee537e3a44b77e3ba09d34d9b3e0";
	logging-data="4187301"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18M5VUfAlLh7/OuR+uAnTx4"
Cancel-Lock: sha1:Obnu0tm6cwFNyIcXnm69CymyzLo=
X-newsreader: xrn 10.11
Bytes: 4259

jgd@cix.co.uk (John Dallman) writes:
>In article <VbrzO.74199$NSs5.15950@fx17.iad>, scott@slp53.sl.home (Scott
>Lurndal) wrote:
>
>> jgd@cix.co.uk (John Dallman) writes:
>> > They're presumably intending to develop high-performance cores, 
>> > since they have substantial experience in doing that for x86-64. 
>> > The question is if demand for those will develop. 
>> Ask Si-Five about demand for high-performance risc-v cores.
>
>SiFive were pretty sure there wasn't near-term demand for them in 4Q2023.

Or maybe there was some other reason that the investor money did not
flow as plentiful as it used to, and so SiFive put the most far-out
projects on the back-burner.

Concerning the demand, RISC-V has the advantage of no ARM tax (and
legal costs like those between ARM and Qualcomm over the developments
started at NUVIA) or the question of AMD64 licensing to third parties.

Another RISC-V advantage is that the government of the USA puts
restrictions on ARM that should not apply to the free RISC-V
architecture.

It would apply to implementations designed in the USA (such as those
by Ahead), but the point is that on the ISA level, and thus the buy-in
into the ecosystem (e.g., from ISVs), RISC-V has an advantage.

RISC-V also has a technical advantage over ARM: It has Ztso (total
store order) as an optional extension, which helps porting of
multi-threaded software from AMD64 (and emulation of AMD64 software).
No such thing on ARMv8 or ARMv9 yet, although implementations like the
Apple M1 and Fujitsu A64FX provide this feature.

>Ahead Computing are presumably not expecting to deliver IP cores for a
>year or two

Three years sounds overly optimistic.  Nuvia was founded in 2019,
acquired in 2021, and hardware has been delivered in 2024, very much
in line with the often-read number of 5 years for CPU design projects.

>But it's also possible they just want to carry on being chip architects
>while being in charge of their own company.

Sure.  But what are the investors seeing in the company?

>If so, adopting RISC-V is
>more credible in the short term than starting to design a new ISA as a
>commercial project.

Certainly.  Establishing another ISA is hard, because it requires
buy-in from many forces for lasting success.  Even if an architecture
has a long track record, like MIPS, that's not enough, as the switch
from the MIPS ISA to RISC-V shows.

RISC-V has quite a bit of mindshare, it lacks the ARM tax, and with
the government of the USA hampering ARM, the RISC-V future looks even
brighter.  They still have quite a way to go.

>Thinking a bit more, they may be trying to go the Nuvia route: design
>original cores for an existing ISA and get bought out.

Probably.  Getting bought is a common outcome of a successful startup.

>Nuvia were bought
>by Qualcomm for their ARMv9-A core IP well before they released anything.

What I read is that the Snapdragon X implements ARM v8.7.

>If Ahead were to successfully design a fast RISC-V core with
>power:performance that was competitive with ARM, /Intel/ might well buy
>them.

Yes, or somebody else, as happened with Nuvia.

- anton
-- 
'Anyone trying for "industrial quality" ISA should avoid undefined behavior.'
  Mitch Alsup, <c17fcd89-f024-40e7-a594-88a85ac10d20o@googlegroups.com>