Comment by silur
7 years ago
I'm a big fan of RISC-V but HiFive completely ruined the whole point. I was excited for a _proper_ open ISA because it would open up super low cost hardware development. But looking at the $35 raspberry pi with a license-bound ARM ISA and a supposedly open source board for $1000 it looks like HiFive is playing by intel's or ARM's rules. No chance for risc-v adoption with this ridiculous overpricing
> But looking at the $35 raspberry pi with a license-bound ARM ISA and a supposedly open source board for $1000 it looks like HiFive is playing by intel's or ARM's rules. No chance for risc-v adoption with this ridiculous overpricing
This is the first revision of a developer board. It is intended for die-hard open source fanatics with money and (this is the real audience) professional developers who want to port operating systems (and perhaps their software) to RISC-V. Such developer boards are always expensive. Cheaper board will become available as soon as this audience is saturated. Then a next (cheaper) revision will be put to market that targets user mode software developers. This revision will still be expensive, but already cheaper. The following revision will target adventurous tinkerers. etc.
And so it trickles down and slowly the price decreases over time. But if you want to take a bet: it will nevertheless stay much more expensive than a Raspberry Pi for a long time.
Indeed. This is a "developer board". They're made with little consequence to cost and they usually cost ghastly amounts compared to what you'd expect out of a standard motherboard.
They're for someone like Western Digital to buy for their devs to develop and test stuff against in their own designs.
The Raspberry Pi is based on an obsolete old graphics chip called Video Core IV with some ARM cores added as an afterthought. Of course it's cheap, it had a 10 year headstart and benefited from the economies of scale of the original product. And as you can figure out almost every SBC is based on old TV boxes (sometimes laptops like RK3399) because that way you can just slap the old SoC on a PCB and sell it without making a completely new SoC. The vast majority of phone SoC's simply do not have the interfaces (often just a single port for USB, network, and eMMC storage, display, perfectly designed for the phone in question) required by SBCs.
In short the production run is very small and that's why it's so expensive. ARM SBCs with custom SoCs cost around the same. Just take a look at linaro's ARM desktop [0] It's $1200 and doesn't even come with 8GB of RAM.
[0] https://www.96boards.org/product/developerbox/
That 24-core Socionext SoC wasn't custom built for Linaro, and in fact more vendors (Orange/Banana whatever) have announced boards based on it.
Such a shame it has A53 cores instead of beefier A72 or newer… I guess Socionext was specifically going for super low power
RISC-V has already been adopted by many companies as low and not-so-low performance embedded microcontrollers. It's just that you don't see it. And it's really perfect for that.
I think that's pretty exciting.
As for super low cost hardware development: you can add a RISC-V CPU to FPGAs with as little as, say, 1500 LUTs, which can be purchased for less than $10.
I don't understand you mean by "proper open ISA".
Do $5000 ARM servers kill the point of the Raspberry Pi?
The point of an open ISA is not "every product made with it is super cheap" (licensing is a tiny aspect of it), and expecting a newly developed, small-volume product to compete with something made by an established player at multiple orders of magnitude larger scale is totally unrealistic.
There's smaller, cheaper RISC-V products out there if you want something risc-v to play with. Serious adoption is going to happen at different places and not bound to "what does an HiFive dev kit cost", that's a rounding error in many places.
Many people are in for a rude awakening when they realize that a free ISA saves them like 1% or less of system cost. It certainly can't overcome the ~10x cost difference between a low-volume prototype board and a mass-produced board.
RPi also kind of ruined the hardware world because AFAIK the SoC was being dumped below cost; I'm not sure if that's still true.
Hard to imagine that the SoC is still being dumped after all of these years, if it even was in the first place.
If the purpose was to kill off the grossly overpriced PC104 market, mission accomplished. The fact that those boards have spawned a zillion competitors seems to suggest that any further dumping is not having the desired effect.
A free ISA is about more than saving a few pennies on each board in royalties, it's about having a chip you can truly trust. One that doesn't have some opaque binary blob running at ring -2. One where nothing is encrypted by a key only the manufacturer (and whomever they can strike a deal with) has. About hardware you truly own and control.
As much as I believe that RISC-V will work its up in the embedded space, I don't think many people care about the "chips you can truly trust" argument.
The moment you're talking ASIC (or even FPGA, with an opaque bitstream), it's anybody'd guess what happens whether you use a RISC-V CPU or not. Even if the known CPU is known to be untainted, a tiny, invisible, additional CPU is sufficient to take over the chip and you'd be none the wiser. The area cost of such an additional CPU would be essentially undetectable, less than 0.01mm2 on a modern process.
Unless you're talking about making your ASIC, but in that case, a commercial offering (which typically comes with a source code license) gives you just as much access to review the code for hidden firmware.
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> A free ISA is about more than saving a few pennies on each board in royalties, it's about having a chip you can truly trust. One that doesn't have some opaque binary blob running at ring -2. One where nothing is encrypted by a key only the manufacturer (and whomever they can strike a deal with) has. About hardware you truly own and control.
This has basically nothing to do with the ISA. It's not the ISA that hides secrets and requires binary blobs. A chip is much more than an instruction set, hence why dealing with the proprietary undocumented garbage to bring up a new ARM SoC is a pain in the ass even if you've memorized every ARM instruction down to its encoding...
If RISC-V gets picked up and used by mainstream chipmakers in the SBC & TV BOX & mobile space, there is no doubt we will end up with chips that have proprietary undocumented garbage interfaces. Just like they also now take something like the (open source) ATF or OP-TEE, implement support for their own chip, and then publish a binary blob without source code.
IIRC, the original RasPi SoC was intended for a Nokia smartphone that was cancelled
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it's about having a chip you can truly trust
This gets repeated over and over but I don't get it. You could build a blob-free ARM chip. Existing RISC-V chips already have/had blobs. Freeeeedom is orthogonal to the ISA.
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> Many people are in for a rude awakening when they realize that a free ISA saves them like 1% or less of system cost.
Actually nobody will have a rude awakening from that as everybody in RISC-V already knows this. That ISA don't matter much for price or performance was mentioned in pretty much every single presentation on RISC-V.
Only by open source fans who don't know much about hardware had such unrealistic expectations.
RISC-V allows for a future of open and costume hardware to be used. There will never be an open hardware RISC-V RPi style board unless you have an open ISA you can build around and use the software base.
Now we have real shot at something like that coming about.
> super low cost hardware development.
There are lots of things that cost money in hardware design, and ISA licensing is a very small part of them.
Edit: I wonder if I should do a rather confrontational blog post telling people why Open hardware is never going to be the free lunch that open source software is..
> I wonder if I should do a rather confrontational blog post telling people why Open hardware is never going to be the free lunch that open source software is..
Bunnie Huang spoke at one of the RISC-V summits on this topic.
> There are lots of things that cost money in hardware design, and ISA licensing is a very small part of them.
Indeed - and this is exactly the point of ISA licensing (and IP blocks): to make it sufficiently cheaper to just license the ISA or IP blocks instead of developing the product from ground up.
Right, but with RISC-V you can actually have some competition to implement RISC-V between multiple vendors, hopefully driving prices down.
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> Open hardware is never going to be the free lunch that open source software is..
Unless we can automate the chip making process. Think of it as the chip version of PCB micromanufacture or 3D printing. At some point someone will make a business out of making boards and placing all the components for you. The trick is to do it without any retooling and no humans involved.
What is the manufacturing cost of a wafer full of, say, CPUs? If we can all get our designs in there, we can share the manufacturing cost.
> What is the manufacturing cost of a wafer full of, say, CPUs? If we can all get our designs in there, we can share the manufacturing cost.
This is called "multi project wafer" or "shuttle service" if you want to look for it.
Actual prices are pretty rare, but I happened to find some: https://nmi.org.uk/wp-content/uploads/2016/11/01-Easy-Access... ; those line up with what I've heard. $25,000 for a few chips from the MPW service, or $100k for your own mask set then $1-2k per wafer.
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Give it some time to mature into a large-scale production. Comparing the cost of what's damn near a developer prototype board to Raspberry Pis manufactured in the millions is like comparing the cost of a yacht to a honda civic.
Check out the LoFive RISC-V development board
Since HiFive is to my knowledge the only ones producing such kind of silicon chips with this instruction set, it is infinitely cheaper than other options, reducing the average price by NaN. I fail to see how more supply for an open architecture raises prices.