[kriro]

Some people care less about squeezing out performance and more about open standards. I like having more choices, especially open ones.

I am a user, I like to tinker, I'm fairly confident there's more than 1% of people who care about these things. If you live in a country that is threatened by export embargos and the like it also makes a lot of sense to prioritize open.

[PunchyHamster]

ISA being open matters very little if chip design isn't and RISC-V isn't going to change much here

[apitman]

The number of companies creating RISC V implementations is pretty hopeful. There's way more competition here than x64 or ARM, and that could yield some interesting results.

[dvdkon]

It matters in that it opens up competition and allows fully-open designs, which should keep prices low and products available, but you're right that having fully-open state-of-the-art chips is unlikely to happen any time soon.

[tw1984]

exactly.

in fact, such ISA is only going to fuel more closed ecosystems as it made hundreds of Chinese vendors to join the game for free, they all suddenly got the chance to build their totally closed platforms.

[LeFantome]

Which makes the whole ecosystem a lot more open. None of those suppliers is going to have the market power to lock you in. You can get it from the lowest cost provider until something higher value comes along.

And if you are a country, nobody can kill your RISC-V ecosystem. Worst case, you have to design your own chips but at least all the software exists and is established. And Ooen Source cores exist and are getting better. They may not be bleeding edge but they could be good enough if push came to shove. The BOOM chip just got vector extensions.

[ThrowawayR2]

Open standards don't mean a thing; you can't execute code on a standard. There are past open ISAs like OpenSPARC, MIPS, and OpenPOWER that never gained any traction.

High performance implementations, i.e. actual chips you can buy, are going to be proprietary and that's not going to change. Engineering hardware is expensive.

[LeFantome]

This is a bold prediction but I thing “alliances” will form where industry players collaborate (like we are seeing in video codecs). And the basic core could become an Open Source project just like Linux did. Operating Systems and codecs were (and are) expensive too.

But there are different levels of proprietary. Having your entire software ecosystem impossible to lock-in means something. And competition tends to breed openness.

MIPS certainly did gain a lot of traction. It was a real force at one point and the world is awash in them. But of course MIPS (the company) is RISC-V now.

[ThrowawayR2]

An operating system can be coded on one not particularly powerful computer by one person and it costs a few pennies to compile and test. A lot of other open source projects were also initiated by one or two talented people. Software is absurdly inexpensive to develop relative to its complexity.

A cutting edge processor requires personnel across several disciplines and millions in specialized equipment to both validate the implementation of the architecture and the electrical behavior of the circuits and each time it's "compiled" (a batch of test chips fabbed and QAed), it takes a few weeks to be delivered and costs hundreds of thousands of dollars. The ISA being open and royalty-free doesn't affect any of those massive costs.

To use a famous quote: "The answer to any question starting, 'Why don't they...' is almost always, 'Money'" Nobody is offering up that kind of money without practical guarantees of success and some kind of profit at the end of it.

[LeFantome]

The idea that a chip takes more "personnel" than an operating system or a codec is wrong. An individual can make toys of either software or hardware. "Real" ones take dozens or hundreds of people. There are 5000 people involved in the Linux kernel. That is design, not production. Production (manufacturing) is what is free in software.

The Linux kernel may be "free" but it represents millions of man hours (or years) of engineering. Creating a viable RISC-V chip would be easier.

Creating the AV2 video codec cost money. I assure you. There is a reason that the Alliance for Open Media is a list of Fortune 500 companies and not a bunch of individual developers.

I have worked in industries dominated by a single chip supplier that made the chips that everybody used. Video surveillance is a good example. It would have been much cheaper for the major players in that industry to fund the collaborative development of chips they could all use and that could maybe be "tweaked" to add differentiated value for the largest players. It would save them money. It would give them more control (even more valuable).

I assume you know what a "chiplet" is. RISC-V is going to change things. In my view, you are focused on the wrong constraints.

We are both saying that money matters. We are simply coming to different conclusions about what that means.

[kjs3]

I'm fairly confident there's more than 1% of people who care about these things

If there were an economically viable number of people who cared about those things (and it would need to be significantly more than 1%), we'd be running SPARC or POWER or maybe SuperH derived systems, all of which have open source, royalty free implementations.

For example, OpenSPARC is something like 20 years old, and covers SPARC v8 through t2. SPARC LEON is a decade older, and is under a GNU license, and has been to space.

And that doesn't consider going the Loongsoon route: take an existing ISA (e.g. MIPS), just use it, but carve off anything problematic (4 instructions covered by patents).

It's a pretty inescapable fact on the ground that in the 'processor hierarchy of needs', an open source license is of no consequence in the actual market.

[LeFantome]

I hesitate to say this as you seem very knowledgeable but you are missing some pretty massive facts that destroy your argument here.

There are already literally billions of RISC-V chips in the wild. Qualcomm alone has shipped a billion or more. They wrote an article back in 2023 where they disclosed that they had already shipped 650 million of them by that point. Andes Technology has said that there are 2 billion chips using their IP. A recent industry report suggested that RISC-V could represent 25% of the global SoC market by 2030. That is based on growth trajectory, not speculation.

RISC-V is not some obscure ISA that cannot get any traction.

There are a dozen or more credible competitors designing modern 64 bit RISC-V CPUs. Most of them have shipped silicon. Some have shipped multiple generations. Has any ISA ever had so many independent companies independently creating core designs (not designs from a single source like ARM)?

Tenstorrent alone likely made $500 million dollars in 2025. Easier to confirm is that they closed a $650 million funding round.

NVIDIA has announced CUDA support for RISC-V. I do not remember them doing that for SPARC, or POWER, or SuperH.

The current RISC-V standard, RVA23, includes advanced instructions for things like vectorization and virtualization. Many large, important industry players are involved in designing future extensions as well.

RISC-V is an officially supported platform in many mainstream Linux distributions including aggressively commercial ones like Red Hat Enterprise Linux but also foundational ones like Debian and its derivatives (like Ubuntu).

GCC and Clang have excellent support for RISC-V. FFMPEG just released hand-written vector optimizations for RISC-V. Again, can we say this about any of the platforms you mentioned?

It's a pretty inescapable fact on the ground that RISC-V has an absolute mountain of support in the industry. And starting this year, multiple vendors will be shipping cores faster than you can license from ARM.

Honestly, what universe are you living in?

[kjs3]

Honestly, what universe are you living in?

The one where I actually read what I'm replying to.

I never one single time said RISC-V wasn't successful. Not even implied it. What I did say, should you ever climb of your apparently thinking-averse, pre-conceived notions is that its license isn't the overriding reason it's successful, because the world is full of open source ISAs that never gained any traction. Something you might be aware of if you took a brief break from furiously jerking off over RISC-V and paid attention.

[tw1984]

> Some people care less about squeezing out performance and more about open standards. I like having more choices, especially open ones.

you need to be totally autistic to believe that Chinese vendors are going to share anything meaningful with you. they don't hate you, they want their paying customers to be happy, but the brutal competitions in China doesn't allow them to be open in any sense. For products like RISC-V processors and MCUs, the moat is extremely low, being open leads to quick death. It is not about how much stuff they share with you as paying customer, it is about how much they are willing to share with their competitors when there are hundreds of companies trying everything to survive.

as a developer, you just need to ask yourself a dead simple question - how such risc-v platforms are going to be more open than raspberry pi.

[LeFantome]

How you heard of Deep Computing?

They are pushing their RISC-V products into the Linux mainline before those products even ship.

Those autistic Chinese also contribute a rather surprising amount of Open Source RISC-V out of their academic world.

[webdevver]

I have increasingly negative things to say about this.

There is (so far) nothing 'open' about RISC-V. and I wonder if there really ever was any desire for it, at this point.

This whole "Open ISA" crap appears to be a thin veneer to funnel quite large sums of investment into an otherwise completely proprietary and locked-down environment that could never harm the incumbents in any meaningful way - while still maintaining just enough of a pretense of open source, that the (regrettably myself included) shallow nerds and geeks could get smitten by it.

Where is the RTL? Where are the GDSII masks? Why am I unable to look at the branch predictor unit in the Github code viewer? Or (God forbid!) the USB/HDMI/GPU IP? I reject the notion that these are unreasonable questions.

I want my SoC to have a special register that has the git SHA ID of the exact snapshot of the repository that was used to cook the masks. that, now that - is Open Source. that is Open Computing. And nothing less!

I dont care about the piece of paper with instruction encodings - the least interesting part of any computer!

Wasn't that the whole point? We're more than a quarter of a century in and we're still begging SoC vendors for datasheets. Really incredibly embarassing and disappointing.

[Shugyousha]

> Where is the RTL? Where are the GDSII masks? Why am I unable to look at the branch predictor unit in the Github code viewer? Or (God forbid!) the USB/HDMI/GPU IP? I reject the notion that these are unreasonable questions.

As you note correctly, the ISA is open, not this CPU (or board).

The important point is that using an open ISA allows you to create your own CPU that implements it. This CPU can then be open (i.e. you providing the RTL, etc.), if you so desire

I assume it will be much more difficult (or impossible?) to provide the RTL for a CPU with an AMD64 ISA, since that one has to be licensed. I wonder if you paying for the license allows you to share your implementation with the world. Even if it does, it's less likely that you will do so, given that you will have to pay for the licensing fee and make your money back

Since there is no license to pay for in case of RISC-V, it allows you to open up the design of your CPU without you having to pay for that privilege

[afiori]

My superficial understanding is that arm does not prevent from sharing implementation details of your own design but most chips also license a starting implementation that has such limitations. So the end result is often more restricted than the ISA licence some would require

[duskwuff]

Most ARM licensees aren't permitted to create custom implementations, only to use IP cores provided by ARM. There are a couple of companies who do have an architectural license, allowing them to create their own implementations, but there are only a few of those and they aren't likely to share. (It's also possible that the terms of their license prohibit them from making their designs public.)

[kjs3]

The important point is that using an open ISA allows you to create your own CPU that implements it.

So? You've been able to do that since...computers. Anyone can roll their own ISA any time they want. It's a low-effort project that someone with maybe a Masters student level of knowledge can do competently. When I was in school, we even had a class where you would cook up an (simple) ISA and implement it (2901 bit-slice processors); these days they use FPGAs.

So you got your own processor for your own ISA...that was slow, expensive (no economy of scale) and without a market. But very fun, and open source, at least. And if "create your own CPU that implements it" is what you want, go forth and conquer...everything you need is already there and has been for a long time.

But if your goal is "I want an open source ISA that I can produce that's price and/or performance competitive with the incumbents", well, that's a totally different ballgame.

And there are open source ISAs that have been around for decades (SPARC, POWER, SuperH). These are ISAs that already have big chunks of ecosystem already in place. The R&D around how to make them competitive already exists. Some, like LEON SPARC have even gone into something like production (and flown in space).

So, yes, an open source ISA affords the possibility that we can make processors based on our own ISAs on our own terms. It has even in extremely rare occasions produced a product. But the fact remains, the market hasn't cared in the slightest to invest what's required to turn that advantage into a real competitor to the incumbent processors.

[LeFantome]

Completely wrong.

Yes, you can create your own ISA. But to run what software?

If I create my own RISC-V implementation, I can install Ubuntu on it. Maybe even Steam.

See the difference?

And, the market has responded with a tidal wave of CPU contenders. Like in the rest of the world, not all of them target the highest end portion of the market. But some are choosing to play there. Have you checked-out Ascalon?

And why did Qualcomm pay all that money for Ventana recently? You do not expect them to release high-end RISC-V chips? I mean, they already ship many low-end ones.

[tw1984]

> And why did Qualcomm pay all that money for Ventana recently? You do not expect them to release high-end RISC-V chips? I mean, they already ship many low-end ones.

Ventana is an extremely bad example to be used here. It is acquisition price is undisclosed, it could be just some $ for acquiring the team behind it. Secondly, Qualcomm's nuvia acquisition was pretty huge, there is no reason whatsoever to believe the Ventana acquisition is remotely comparable, that proves no one uses RISC-V anyway.

[LeFantome]

> no uses RISC-V anyway

Here is an article from a company called Qualcomm from two years ago saying that they had, at that time, already shipped 650 million RISC-V cores.

https://www.qualcomm.com/news/onq/2023/09/what-is-risc-v-and...

I notice that the three benefits they flag for RISC-V are: flexibility, control, and visibility.

I wonder how they felt about "control" after ARM tried to stop them from commercializing the value of their Nuvia acquisition? I wonder if it had anything to do with their next big acquisition being RISC-V based instead?

I also wonder, why on their Oryon page does Qualcomm never meanion ARM. Not even once. Even to the question, is Oryon x86, they do not answer that it is ARM. Why not?

https://www.qualcomm.com/processors/oryon

[kjs3]

Why don't you read what was written instead of being the unthinking RISC-V fanboi in the room. My only point was that the RISC-V license is probably not the biggest factor in its success, since there have been many, many open source ISAs that weren't successful.

[camel-cdr]

https://tutorial.xiangshan.cc/hpca25/slides/20250302-HPCA25-...

[ksec]

Couldn't have said it better. The moments these people promise everything would be free is a massive red flag. Unfortunately it seems most poodle haven't learned the lesson.

[afiori]

It is a free non-copyleft licence, it is the expected result that derivatives are not similarly free

[tw1984]

> There is (so far) nothing 'open' about RISC-V.

with the majority players being Chinese vendors (those you can buy, not including those building RISC-V for their own in-house applications), RISC-V is far less open than ARM or x64.

expecting openness from Chinese vendors is like trying to hook up with some virgin bar girls in your favourite gogo bar in Bangkok.

[LeFantome]

Get your virgin bar girls here…

https://github.com/OpenXiangShan/XiangShan

[tw1984]

are you joking?

if you search their public media releases, they mentioned that their cores are used by some imaginary vendors for undisclosed platforms. just go and check how CLOSE those junks are. product names and models are always omitted, it is always "certain vendor", "one AI card", no spec no details whatsoever...

searching their names on taobao.com returns 0 hit, searching their names on the largest Chinese second hand platform returns 0 hit. 4 years after they started doing their great open project, you can't even buy one from the OPEN market! that is VERY OPEN to me.

[LeFantome]

Holy swerving goal-posts Batman.

Ok fine. Here is a link to a completely open design:

https://github.com/tenstorrent/riscv-ocelot

And here is a high-performance evolution of it that you can license. They would be happy to take your check today. https://tenstorrent.com/ip/risc-v-cpu

Silicon will be available in a few months.

And just for you, it is not Chinese.

[apitman]

The RP2350 has a couple Hazard3 cores in it.

[LeFantome]

Indeed

https://github.com/Wren6991/Hazard3

[swaits]

“People who care about these things” enough that they’re buying Mini ITX RV motherboards? Definitely well under 1% of the market.