[tails4e]

RISC-V is not immune from license fees, unless you want to design a high performance core from the ground up. If you want something as capable as an M4, there is years of R&D to get to that level. I'm sure a big player could do just that in house, but many would license Si-Five or similar. It will be interesting to see if Qualcomm and the like would make a move towards RISC-V, given their ARM legal issues

[ryao]

There are an incredible number of companies designing their own RISC-V cores right now. Some of them are even are making some of their designs entirely open source so that they are royalty free. The highest end designs are not, but it is hard to imagine their creators not undercutting ARM’s license fees since that is money that they would not have otherwise.

As for Qualcomm, they won the lawsuit ARM filed against them. Changing from ARM to RISC-V would delay their ambition to take marketshare from Intel and AMD, so they are likely content to continue paying ARM royalties because they have their eyes on a much bigger prize. It also came out during the lawsuit that Qualcomm considers their in-house design team to be saving them billions of dollars in ARM royalty fees, since they only need to pay royalties for the ISA and nothing else when they use their own in-house designs.

[theupsidedown]

I doubt open source designs are going to be competitive with closed source. Also, design is just part of the problem. There is a whole lot of other things you need to get a chip out. I do not think RISC-V chips will be cheaper than other architecture when you take everything into account.

[ryao]

It is funny that you should say that, considering that I was wondering this myself earlier today WRT the Hazard3 cores in the RP2350. It turns out someone did benchmarks:

https://icircuit.net/benchmarking-raspberry-pi-pico-2/3983

The Hazard3 core was designed by a single person while the ARM Cortex cores were presumably designed by a team of people. The Hazard3 cores mostly outperforms the Cortex-M0+ cores in the older RP2040 and are competitive with the Cortex-M33 cores that share the RP2350 silicon. For integer addition and multiplication, they actually outperform the Cortex-M33 cores. Before you point out that they lost most of the benchmarks against the Cortex-M33 cores, let me clarify that the integer addition and multiplication performance matter far more for microcontrollers than the other tests, which is why I consider them to be competitive despite the losses. The Hazard3 cores are open source:

https://github.com/Wren6991/Hazard3

That said, not all RISC-V designs are open source, but some of the open source ones are performance competitive with higher end closed source cores, such as the SonicBoom core from Berkeley:

https://adept.eecs.berkeley.edu/wiki/_media/eop/adept-eop-je...

As for the other problem you cite, the RP2350 has both RISC-V and ARM cores. It is a certainty that if the ARM cores had not been present, the RP2350 would have been cheaper, since less die area would have been needed and ARM license fees would have been avoided.

[fidotron]

RISC-V implementations are going to prove to be absolute patent minefields.

Just because something is open source will not stop you from being stung during manufacturing, rather like how Android deployments are not free.

[ryao]

So far, patent lawsuits have been more of a problem for those using ARM designs (Qualcomm) than those using RISC-V designs. The Raspberry Pi foundation, Western Digital and Nvidia have successfully put RISC-V designs into their products without any issues. The first two even made their core designs open source (see Hazard3 and SweRV).

[fidotron]

How are SiFive going to protect their IP when everyone is free to copy it?

Patents.

[RetroTechie]

You're not free to copy SiFive's IP cores.

Open ISA != all implementations of it are free (although in RISC-V case, many are).

[fidotron]

Sorry, that was poorly worded.

My point is that if RISC-V takes off people will struggle to do decent implementations of it without stepping on the toes of the people already in the area.

I'd go so far as to say this is the entire SiFive strategy.

[ryao]

Anyone is free to make a RISC-V CPU without infringing on SiFive’s IP.

[fidotron]

Which in practice will mean free to make simplistic implementations using the lessons of twenty years ago.

If this was a winning strategy those open source implementations of SuperH cores would have been incredibly popular instead of dying in obscurity.

[xbmcuser]

China will likely be the country taking forward RISC-V and ditching Arm and x86 completely. With USA trying to stop other countries from using latest Chinese tech they are given more reason to ditch any and all propitiatory US tech. So over the next decade I expect RISC-V architecture to enter and flood all Chinese tech devices from Tvs to cars and everything else that needs a CPU.

I personally hope China get's competitive in the node size as well as I want gpu and cpus start getting cheaper every generation again as once TSMC got big lead over Intel/Samsung and Nvidia got a big lead over AMD prices have stopped coming down generation to generation for CPU's and GPU's

[ryao]

RISC-V is definitely gaining traction in China, but it does not have a monopoly on Chinese CPU core design:

  * Loongson is pushing a MIPS derivative forward.
  * Sugon is pushing a x86 derivative (originally derived from AMD Zen) forward
  * Zhaoxin is pushing a x86 derivative (derived from VIA’s chips) forward.

There was Shenwei with its Alpha processor derivative, but that effort has not had any announcements in years. However, there is still ARM China. Tianjin Phytium and HiSilicon continue to design ARM cores presumably under license from ARM China. There are probably others I missed.

There is also substantial RISC-V development outside of China. Some notable ones are:

  * SiFive - They are the first company to be in this space and are behind many of the early/current designs.
  * Tenstorrent - This company has Jim Keller and people formerly from Apple’s chip design team and others. They have high performance designs up to 8-wide.
  * Ventana - They claim to have a high performance core design that is 15-wide.
  * AheadComputing - they hired Intel’s Oregon design team to design high performance RISC-V cores after the Royal Core project was cancelled last year.
  * The Raspberry Pi foundation - their RP2350 contains Hazard3 RISC-V cores designed by one of their engineers.
  * Nvidia - They design RISC-V cores for the microcontrollers in their GPUs, of which the GPU System Processor is the most well known. They ship billions of RISC-V cores each year as part of their GPUs. This is despite using ARM for the high end CPUs that they sell to the community.
  * Western Digital - Like Nvidia, they design RISC-V cores for use in their products. They are particularly notable because they released the SweRV Core as open source.
  * Meta - They are making in-house RISC-V based chips for AI training/inference.

This is a short list. It would be relatively easy to assemble a list of dozens of companies designing RISC-V cores outside of China if one tried.

[xbmcuser]

USA has now started banning companies of other countries from using Chinese tech if the Chinese tech has US components its a big over reach but it will move Chinese tech companies to move away from any US propitiatory tech.

https://www.bis.gov/media/documents/general-prohibition-10-g...

[ryao]

That is not what your link says, but regardless of the details, Chinese companies are free to do whatever they want if they have no interest in exporting their products outside of China. Many do not care about markets outside of China. It is unlikely that China will drop all other ISAs in favor of RISC-V, especially since x86 and ARM are just as dominant in China as they are in other countries.

[xbmcuser]

But that is the thing China wants to move on to exporting high value items themselves instead of manufacturing it for others and letting them take most of the profits. The bans and stuff has just started but this will result in China moving towards RISC-V the same way export of latest node tech has resulted in China doing it themselves and rapidly catching up. If you read my original comment what I said was over the next decade China will move away from Arm and x86 for RISC-V. It takes years to plan and built devices 5-6 years from now we will find out what I am predicting comes true or not.

[ryao]

You should not reason about China as a monolithic entity. China has a population of 1.4 billion people. Some look outward while others look inward. Those looking outward are interested in RISC-V for certain things since it is not subject to U.S. export controls (so far).

China is unlikely to move away from x86 and ARM internally even in a 10 year span. The only way that would happen is if RISC-V convinces the rest of the world to move away from those architectures in such a short span of time. ISA lock-in from legacy software is a deterrent for migration in China just as much as it is in any other country.

By the way, RISC-V is considered a foreign ISA in China, while the MIPS-derived LoongArch is considered (or at least marketed as) a domestic ISA. If the Chinese make a push to use domestic technology, RISC-V would be at a disadvantage, unless it is rebranded like MIPS was.

[bobmcnamara]

They've already exfiltrated Arm's IP and began designing their own Arm cores. Is there a need for them to switch?

[rollcat]

Correct me if I am wrong, but in RISC-V's case, you would be licensing the core design alone, not a license for the ISA plus the core on top.

Right now, AFAIK only Apple is serious about designing their own ARM cores, while there are multiple competing implementations for RISC-V (which are still way behind both ARM and x86, but slooowly making their way).

VERY long-term, I expect RISC-V to become more competitive, unless whoever-owns-ARM-at-the-time adjusts strategy.

Either way, I'm glad to see competition after decades of Intel/x86 dominance.

[ryao]

Qualcomm has a serious development effort in their Oryon CPU cores. Marvel had ThunderX from the Cavium acquisition, but they seem to have discontinued development.

[solarkraft]

Yes, but the playing field is different. Anyone can become a Risc-V IP provider and many such companies have already been created.