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Comment by sweden | Hacker News Reader

RISC-V is thrown around like if it's an already working CPU but it is not. It is just a document describing an ISA, you can't compare it to Linux, it's a completely different thing.

There are a lot of costs in implementing an ISA and that includes: design, functional verification, physical implementation and software testing. All those steps together will require hundreds and hundreds of engineers, many expensive tools and thousands of man-hours. And once you are done, you will need to find be careful not to violate any patents while shipping your CPU to the end customer.

By paying a license fee to ARM, you get all these steps done for you plus with support.

Linux is something that you can download from kernel.org, compile overnight and get it booting right away. RISC-V is something that you need to build yourself.

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When I did a presentation on RISC-V last year I counted 6 real implementations (full custom ASICs). Now granted only one or two of those you can buy, the others are research projects, but they do exist and they did produce real silicon. This year we should see a couple of 64 bit implementations, which is when it'll get really interesting.

There are of course multiple FPGA implementations (I have one about 2 feet away from me now), but they are very slow.

I am aware that they exist but it's not like companies are going to actively invest in devices for the end consumer purely based on RISC-V.

From where I'm standing, it looks like you're shifting goalposts:

> > RISC-V is thrown around like if it's an already working CPU but it is not

(Evidence of existing CPUs provided)

> I am aware that they exist but it's not like companies are going to actively invest in devices for the end consumer purely based on RISC-V.

My point is, you can't get those existing CPUs for free.

What kind of for free are you talking? The first commercial run RISC-V microcontroller SoC has fully-published RTL, and a company which will support you in adding it to your products (SiFive). Obviously people aren't going to give you the manufactured chips for free, but how close do you want it?

Is your presentation online?

No it was a private talk about company strategy.

Linux didn't instantly become something you could download from kernel.org, compile overnight and get it booting right away. It took hundreds and hundreds of developers, thousands of man hours, financial investments from a large number of companies worldwide and many many years for Linux to become what it is today. All of this done while there were several existing commercial Unix variants which could have been licensed instead.

During its early years many scoffed at it as you have RISC-V. "It is a hobby OS. It will never be able to really compete with the likes of Solaris, HP-UX, and AIX. Heck, it won't even be able to compete with SCO and Unixware."

I'm not saying that RISC-V is an hobby project, I'm just saying that hardware development is nowhere comparable to software development.

You need much more support and verification while developing hardware then developing software. And while you can reuse the functional design (please note the keyword "functional"), the physical implementation needs to be redone from project to project.

ARM, Intel, AMD, Apple and Qualcomm have an army of engineers with all kinds of tools that go through all the steps of hardware design and implementation which you can't do as a side project at home using just your computer.

Linux is still a hobby OS. It's not a particularly wonderful example of software engineering. Its only real benefit is that it's free and comes with an ecosystem of other free software that kind of mostly works as long as you don't mind the occasional security horror, and can be used as-is or customised at relatively low cost.

That combination of features makes it appealing in a variety of business cases - for business reasons.

RISC-V can't be customised at relatively low cost. It's nominally free, but the freeness doesn't mean much in a business setting.

The total cost of developing a custom core remains beyond the reach of small companies.

Big companies already know there's an established ARM ecosystem with working compilers and a simple, risk-free, and relatively affordable business model.

So what business problem does RISC-V solve?

"Linux is still a hobby OS. It's not a particularly wonderful example of software engineering. Its only real benefit is that it's free and comes with an ecosystem of other free software that kind of mostly works as long as you don't mind the occasional security horror, and can be used as-is or customised at relatively low cost."

That is complete nonsense. Linux, particularly Red Hat Enterprise Linux is as serious of a server OS as exists in the world today. Companies like IBM and Oracle would never embrace a "hobby" OS in an enterprise setting.

As for "occasional security horrors", sadly there is no OS of any flavor that is immune.

"So what business problem does RISC-V solve?"

For one thing, RISC-V offers the promise of fully open computer systems, without opaque black boxes anywhere providing potential back doors or other problems. The Intel AMT vulnerability is an excellent example of how that can go very wrong:

https://www.ssh.com/vulnerability/intel-amt/

RISC-V also provides a playground for smaller entities (like university labs) wishing to experiment with innovative new hardware techniques like Unums. That's very valuable in its own right.

http://web.stanford.edu/class/ee380/Abstracts/170201-slides....

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