alt Hacker NewsI think he's kind of speaking past the original author. The original piece is basically about how the author doesn't think that RISC-V will take off outside embedded, because of some design decisions that lead to poor performance compared to ARM64 and because so much of the ISA being optional means that there's too much fragmentation to make binary distribution feasible. Meanwhile, this piece is mainly about how RISC-V is great for embedded because companies can build it into custom chips with specifically the functionality they need, and because of how cheap it is for low-end use cases since there's no license fees.
The only real point of contention I see between the two is that this piece goes on to talk about how it's a selling point that RISC-V can be used for both low-end 10 cent microcontrollers, and high-end multi-core processors running Linux. Personally I don't see the benefit of this since you're going to have to recompile your software anyway, and since all the RISC-V SBCs I'm aware of have significantly worse performance and efficiency than comparably priced ARM SBCs.
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The huge number of companies building RISC-V chips and really crazy optimizations that they are doing in all kinds of spaces are a very real counterweight to your notion.
And RISC-V is just starting here with shoestring design and fab budget. Wait till all engineering teams really adopt it like Tenstorrent and NextSilicon and so on.
> Personally I don't see the benefit of this since you're going to have to recompile your software anyway
The benefit is a unified toolchain. Make a chip, get the entire software toolchain for free.
In the past if you made your own chip you had to write your own assembler, compiler, debugger, etc. Many manufacturers forked gcc but of course it's still a lot of work and the license isn't great (for them, not the user).
This universal compiler toolchain is massive benefit for both the chip makers and the end user.
Different RISC-V dialects might as well be as different from each other as English is from German. Sure, the cognates, family the resemblance, and common(-ish) alphabet make some things easier, but if you're shipping a manual, you still need to do it both in English and auf Deutsch unless you rely on machine translation.
So it is with the family of mutually incomprehensible ISAs called RISC-V.
The two authors also have a very different definition of what "high-end" means.
Dmitry is talking about high-end application processors that you might find in a mid-range or better laptop, smartphone or server. Armstrong Subero seems to think that anything larger than a "dirt cheap microcontroller" is high-end.
People shouldn't take this the wrong way, but the VexRISC-V cores in Baochip are not "high-end". They are basically as low-end as you can get while still meeting the modern definition of "application core". And that doesn't matter, because being high-end application SoC is not Baochip's design criteria. These cores are actually pretty decent for Baochip's criteria.
The VexRISC-V are implementing the exact style of "classic-RISC" microarchitecture that RISC-V is optimised for. It's basically the optimal niche for RISC-V, before any of the problems start showing up.
I don't think I've ever seen anyone express the opinion that RISC-V can't easily cover the "dirt cheap microcontroller" to "low-end application processor" range, even stretching up into "mid-range application processor". Just that it's really fighting an uphill battle if it ever wants to compete with high-end application processors (and that it's going to struggle in the low-range/mid-range application market because of that).