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Comment by mhh__ | Hacker News Reader

If it becomes an issue ARM probably will change dramatically, however keep in mind RISC-V let's you licence hundreds of probably pretty crummy cores (and a handful of good ones) whereas ARMs are battle tested, verified, and come with documentation. RISC-V docs are still a bit 1980s i.e. as far as I'm aware there's no official online source of HTML docs, and not as much blessed software as arm (i.e. compilers tested in-sync with the ISA). Oh and people to sue...

I also trust the ARM ISA designers more than the RISC-V ones, but I don't know enough that you should trust me.

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As a hobbyist I see this from a very different perspective. ARM documentation is overwhelming and ironically ARM is confusing as hell to read about due to its fragmentation into 32-bit and 64-bit ARM as well as Thumb1 and Thumb2. I don't have a great memory, and I really get lost when reading ARM tutorials and docs.

RISC-V for hobbyist like me is just WAY WAY easier to deal with. There is a great consistency between RISC-V 32-bit and 64-bit which ARM lacks. There is just one compressed ISA and it maps to the regular one in straight away manner. Register naming is more sensible and consistent.

ARM instructions with their complex addressing modes are not easy to read. ARM vector instructions makes your head explode trying to keep all the details in your head at the same time. RISC-V vector instructions are just way easier to grasp.

In many ways it reminds me of the documentation situation with Python vs Julia. Python has more documentation for sure, but a big problem with that is all the stuff that is outdated irrelevant, combined with the difference between Python 2.x and Python 3.x although that has gotten easier in recent years.

New technologies will always have less documentation but they often benefit from not having lots of legacy which complicates understanding.

At least ARM is easier than x86, but that is a pretty low bar.

The year is 2012. Blender is an open source 3D modeling and CG software. There are hundreds of crummy plugins and hacks (and a handful of good ones,) whereas Maya is battle tested, developed by professional Autodesk engineers. It comes with good documentation and support. Blender documentation and tutorials were essentially youtube videos with cheesy electronic music in the background. (I'm probably getting some details wrong, but you get the point.)

You're not wrong in your assessment. However you're looking at it as it is right now, as opposed to where it's headed for in the future and what it could ultimately become. While CG and computer hardware are very different fields, the effects of communal knowledge sharing are very similar and very powerful. When bored high schoolers and broke college kids (and curious adults) can tinker with the tech, they enter the industry with that much more experience and/or have another avenue for career transition. And that is far more valuable than the mild (and sometimes nonexistent) conveniences of ARM over RISC-V.

Writing code for Blender != Developing a high performance core that is going to be fabricated on TSMC's leading edge process.

In the first case anyone with the right skills can do it. In the second you need access to lots of specialist tools / proprietary industry knowledge.

If RISC-V 'wins' in application processors it will be because an Intel or a Qualcomm invests (probably) hundreds of millions in building a team that works on a multi year project. It definitely won't be bored high schoolers.

Shockingly this is not strictly the case anymore and it's become less true everyday.

https://info.efabless.com/press-release-efabless-launches-ch...

130nm - that was leading edge 20 years ago.

That means we are only 20 years away from running everything on opensource hardware.

Who says you have to fabricate a RISC-V processor on leading edge TSMC nodes? What about FPGAs? What about older nodes? The whole point of my argument is that when you make the proprietary "industry" knowledge more generally available, more people can contribute to the ecosystem as it removes barriers to entry.

> In the first case anyone with the right skills can do it. In the second you need access to lots of specialist tools / proprietary industry knowledge.

In the first case, it used to require specialist tools like the Autodesk suite, and people had to have access to that software to develop the right skills and acquire the industry knowledge.

I don't think RISC-V "winning" is the right way of measuring success. Whether or not it becomes the dominant ISA for everything is irrelevant. It serves an important role in our market and it doesn't need the guys at Qualcomm and Intel to use it to make it successful. Either way Intel is investing big money into RISC-V: https://www.zdnet.com/article/intel-invests-in-open-source-r...

Also, careful what you say about high schoolers: https://riscv.org/blog/2020/11/13-year-old-nicholas-sharkey-...

Fair enough and I don’t disagree at all but I do think it’s a bit different to software development on that there is probably a limit to how far you can go without one firm spending serious money. As you say it may be Intel - which doesn’t really give me a warm glow.

I'm sorry to say there does seem to be a certain lack of respect for the Arm ISA designers floating around. Arm v8 is in billions of smartphones and powers the core with the fastest single threaded performance out there, but somehow it's obviously inferior and will be supplanted.

> I'm sorry to say there does seem to be a certain lack of respect for the Arm ISA designers floating around.

I was going to use that exact wording in a different comment but decided against it, spooky

That is spooky!

I mean there was clearly a lot of analysis put into aarch64 - which probably involved Apple etc - but I've seen comments previously saying they obviously got it wrong because [insert some headline design decision].

They might have got it wrong but they're definitely not amateurs at this and you can't prove anything with a one line comment.

I guess the point is, given the eye balls RISC-V is going to attract, you'd have your Tencents and Apples of the world pouring resources into it, just like they did with AARCH64. And when that happens, where does ARM, as a company, go? They did to Intel what RISC-V is poised to do to them, may be in a decade or two.

I feel ARM could go the Docker way, who faced a similar foe in the stakeholders seeking to commoditize their core business... ruthlessly stomped on them, creating k8s, runc, registries, microvms, serverless, and what-not. Despite Docker having stellar engs working for them (and in some cases, better tech: Swarm, for instance), there's nothing they could do.

Why would Apple pour resources into it? To save a few cents licensing costs on a $1,000 smartphone and give up a decade of hardware and software investment. Sorry, not buying it.

Apple already have a "We can do whatever the fuck we want" licence on aarch64 anyway, notice how they've been adding their own instructions?

> you'd have your Tencents and Apples of the world pouring resources into it

The Tencent and Apple of the world are...Tencent and Apple.

If Amazon say decided to throw billions at developing a Graviton 4 using RISC-V...they really couldn't leverage much of their previous Graviton development work. They also wouldn't have a deep bench of low level RISC-V wunderkind to bring on board to leverage the new platform. It's a chicken and egg problem.

Why would Amazon then want to pay to bootstrap a whole RISC-V market? That's a lot of CapEx without a clear potential for returns. You'll note they did develop Graviton using the ARM ISA so they didn't have to create from whole cloth a "Graviton" market.

Amazon made the same decision as PC makers in the 80s. They consolidated around the IBM clone architecture to take advantage of the rest of the market, especially Microsoft and IBM, supporting the IBM clone market. Commodore, Atari, and Apple all had to fight uphill against IBM clone market.

I haven't seen any technical advantage of RISC-V over ARM that would suggest it's worth pouring billions of development dollars into. It might make sense for Western Digital for drive controllers but not phone, tablet, PC, or server makers.

> I haven't seen any technical advantage

RISC-V has geopolitical advantage however in that it's not controlled by US/UK.

I can see why Amazon wouldn't pay to bootstrap that, but I can see why Tencent/Huawai/Alibaba would try to.

AFAIU all the Graviton chips so far are using off the shelf cores licensed from Arm. What Amazon is doing is assembling a shopping list of cores, peripherals (probably also to a significant extent licensed from Arm rather than a 3rd party or even in-house) etc. and creating a SoC, which is manufactured by someone else. Even this is no walk in the park, I'm sure Amazon has hundreds(?) of engineers working on Graviton.

Now, if someone would create a RISC-V core competitive with the Arm server cores, and an ecosystem of RISC-V compatible peripherals (well, not compatible in the sense that some random peripheral would need to care about the ISA, but that Arm might not want to licenses their peripherals to a RISC-V based project?) shows up, I'm sure Amazon could do roughly the same with a hypothetical RISC-V Graviton. But if you're talking about designing a RISC-V core from scratch, that's a whole different ballgame.

> AFAIU all the Graviton chips so far are using off the shelf cores licensed from Arm. What Amazon is doing is assembling a shopping list of cores, peripherals (probably also to a significant extent licensed from Arm rather than a 3rd party or even in-house) etc.

This is my point. Amazon using ARM lets them tap into the huge ARM ecosystem with minimal investment on their part. The cores they're using have known qualities and meet whatever performance targets they want.

At this point RISC-V doesn't have that same ecosystem. It doesn't even have extant high performance cores someone can just order. Building momentum is expensive. If selling that ecosystem isn't your main business it's probably not worth investing millions or billions to develop it.

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