[HN Gopher] Ask HN: What does RISC-V custom chips for under $100...
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Ask HN: What does RISC-V custom chips for under $100K mean?
In 2016, SiFive blogged about custom chips for under $100K[1]. What
does this mean in practice for a business? What does a business get
if they give SiFive $100K? Does the business have to give SiFive
anything in addition to $100K such as a schematic? What are the
steps between giving SiFive $100K and getting physical chips in
your hands? > At the workshop, people asked me what it would cost
to make a chip with SiFive. The room went quiet ... people expected
me to dance around the topic (like all other people do). Jaws
dropped when I simply said "system architects and designers can get
customized chips for less than $100,000" - less than the cost of
just licensing most CPUs today. [1]
https://www.sifive.com/blog/custom-chips-for-under-100k
Author : zkirill
Score : 87 points
Date : 2024-06-19 09:36 UTC (13 hours ago)
| brucehoult wrote:
| In 2016 that would be a E31 core, user-specified amount of data
| SRAM and icache (also SRAM), XIP from external SPI flash, user-
| specified number of GPIOs. Possibly integrating some simple
| customer peripheral IP as a memory-mapped device, or MAYBE with a
| simple custom instruction as a functional unit, SiFive doing a
| little NRE on that, and doing a $30k 180nm shuttle run giving
| ~300 chips.
|
| If you could give SiFive your desired peripheral or custom
| instruction already integrated with Rocket and working on an FPGA
| (Arty) then you'd get it for under $100k for sure -- if you made
| SiFive do the work it would rapidly get to be more.
|
| Disclaimer: I was an early customer for the HiFive1 (December
| 2016) and then worked at SiFive from early 2018 to early 2020,
| but I don't speak for them.
| zkirill wrote:
| Thanks for replying! This is one of those moments when one is
| reminded how amazing HN can be.
|
| So, for example, if a business sends SiFive $100K and a copy of
| OpenRISC, they would receive ~300 chips that could then be used
| in a commercial product?
|
| If a business then wants to order another 300 chips (or more),
| would they only need to pay SiFive the $30K? Does the $30K
| price fluctuate? Does E31 core have an end of life? In the
| event that EOL is reached, or SiFive ceases to exist, can the
| business make these chips somewhere else or are they screwed?
| brucehoult wrote:
| I suspect SiFive wouldn't be too interesting in doing that.
| First off, OR1K is a lot bigger than an E31. And it's only a
| core, not an SoC. You're probably looking at a several
| million dollar job for that.
|
| Plus SiFive divested their chipmaking division, OpenFive
| (formerly Open-Silicon) in 2022. That would be who you'd want
| to talk to.
| vessenes wrote:
| Quick note - I've been where you are on hardware, which I
| imagine is "interested and curious and might have a use
| case". Silicon is an industry that is _related_ to software,
| but in no way the same, and it's a fairly complex stack, with
| its own unique supply chains and considerations.
|
| All that said, if you're exploring, have fun! If you're
| getting serious I'd recommend you find someone who can help
| you navigate it; there are many surprising things to learn as
| you go.
|
| For instance, to answer your question on chips: all chips are
| made by 'taping out' - a process that yields the masks that
| can be used to make chips. These are only good with a
| specific chip maker, and will live with that chip maker near
| the hardware that is used to make the chips forever. It's
| expensive to design the chip, and expensive to tape out, but
| once you have something it's relatively cheap to make more of
| them.
|
| 180nm is potato quality - many many generations behind. So
| far behind it might actually be more expensive to get chips
| than at 110/65nm, although I'm only speculating here.
|
| A shuttle run means the vendor is going to put your chip
| designs onto a wafer with a bunch of other ones at the same
| time; it's a way to share out the costs for a tape out with
| other customers. The general idea of a 180nm tape out is
| likely that you want some parts to test in your
| infrastructure / build ahead of your full launch. Think of it
| like a compile with -debug turned all the way up.
|
| Usually you'd then either adjust the design and re-do a
| shuttle run (your compile turned up real problems or your use
| case changed), or you'd shrink and make your own wafer, (turn
| on optimization and compile for deployment). Shrinking from
| 180 to 110 or 65 is likely almost totally an automatic
| process these days; as you go smaller, analog physics makes
| this challenging.
|
| So, upshot: you _probably_ could ask for another shuttle run,
| but you'd have a higher part cost than your first run because
| you'd be paying for the whole wafer alone this time, but only
| able to use the part that has your chips on it.
|
| And, you'd need to be in a world where you really wanted
| another 300 chips of the same potato speed (and possibly
| quality) as your first run. Most likely a silicon consultant
| would find a more efficient use case for your needs, whether
| that's a small geometry FPGA that is programmable, an
| existing chip (there are A LOT of chips in the world), or
| some other solution.
|
| Anyway, have fun if you get into it -- fascinating world.
| throwup238 wrote:
| 180nm is "potato quality" but still commonly used for
| automotive chips like PMICs. Though I suspect you're right
| that a newer node would cost the same.
|
| 180 nm fabs are getting to the point where replacing
| machines is prohibitively expensive and spare parts have to
| be custom made.
| dfgs234 wrote:
| > 180 nm fabs are getting to the point where replacing
| machines is prohibitively expensive and spare parts have
| to be custom made.
|
| Do you have a reference for that? I'm not sure why it
| would be true.
|
| 180nm lines have many other advantages, like better
| transistor gain for analog, lower leakage, more advanced
| device types and BCD. Some 180nm lines can also do MEMS.
| Maybe a couple of foundries are struggling but I would've
| thought 180nm was still going pretty strong.
| throwup238 wrote:
| 180nm is still going plenty strong and the fabs get a
| constant stream of upgrades, but the lithography systems
| are officially EOL. ASML/Nikon/Canon don't make them
| anymore except for the occasional ( _very_ expensive)
| custom order and the cost of repairing them is steadily
| increasing. If they don't need the bigger node size,
| greenfield projects are better off with a smaller node
| but anyone with an existing design is going to keep using
| it.
|
| It's just a cost-curve thing - older nodes eventually hit
| the other end of the bathtub curve where keeping the fab
| running gets more and more expensive while newer nodes
| are still cheap.
| dfgs234 wrote:
| That doesn't really match my experience. I could be
| totally wrong though because I don't get to look at the
| books.
|
| ASML it still announcing DUV systems on their product
| page. I would think this would mean they would be very
| happy to sell you a new one.
| https://www.asml.com/en/products/duv-lithography-systems
|
| And machine revitalization and refurbishment is an
| important selling point for this kind of capital
| equipment.
|
| https://www.asml.com/en/news/stories/2023/revitalization-
| thr...
|
| "Did you know that approximately 95% of ASML lithography
| systems sold in the past 30 years are still active in the
| field? As of the end of 2022, more than 5,000 of our
| machines are hard at work in chipmaking fabs globally - a
| feat made possible by the fact that our systems can be
| repaired, refurbished and repurposed throughout their
| life cycles. It's all part of our commitment to
| supporting a circular economy in the semiconductor
| industry that reduces waste, adds value and lessens
| environmental impact."
|
| "Currently there's a growing market in the semiconductor
| industry for mature DUV technology solutions. Refurbished
| systems provide cost-effective options for chipmakers
| looking to scale up in that area."
| throwup238 wrote:
| Those TwinScan systems are much newer than the PAS5500
| series I'm familiar with (the one they're really bragging
| about in that article with the 95% stat). ASML doesn't
| sell them anymore, they only offer the refurbishment
| program: https://www.asml.com/en/products/refurbished-
| systems
|
| Sooner rather than later it'll be cheaper to buy a
| TwinScan system than to fix a PAS5500/750, but at that
| point why would the fab keep making 180nm chips when they
| can make more money making 45nm chips with the same
| system? Last I checked, some critical parts already had
| 1+ year lead times because they had to be made to order
| so fabs have to keep their own stock.
|
| Edit: Sorry I misused "EOL" in a previous comment.
| They're still being supported my ASML, but you can't buy
| a new machine so expanding a fab means upgrading the
| node.
| dfgs234 wrote:
| I suppose it depends what they're printing and why. There
| are plenty of structures that will want to be 180nm and
| larger for many years to come.
|
| But I definitely agree that pretty soon it will make no
| sense to artificially limit printing resolution and, for
| high volume manufacturing, buying a new machine that
| can't do better than 180nm will make little sense.
| bgnn wrote:
| TSMC is phasing out 180nm officially already for 2 years
| due to demand on more advanced nodes like 65nm or 40nm.
| All the BCD stuff is implemented on those processes too.
| They are moving the equipment used in 180nm to these
| newer nodes. I think they don't want anything laeger than
| 110nm.
| nine_k wrote:
| Likely 180 nm is fine when you have little and slow
| logic, don't care about power efficiency too much, and
| want to integrate output pins rated at 500 mA. Much of
| car electronics is like this.
| pjc50 wrote:
| Can confirm that lots of our ~10 year old designs are
| getting a re-spin on newer processes for exactly this
| reason. The availability of the old ones is going down.
|
| As for "can you order more if SiFive goes out of business":
| the detail here is going to be in all the _other_ bits on
| the chip. Maybe they 're free licensed, maybe they're not.
| You probably wouldn't get the GDSII that SiFive sent to the
| fab. You'd need to arrange another shuttle run. You might
| be too small for the fab to return your calls.
|
| It's a pretty niche kind of manufacturing activity. Not
| many businesses _really_ need a custom CPU.
| withinboredom wrote:
| > You might be too small for the fab to return your
| calls.
|
| How long till there is a self-service SaaS for this?
| convolvatron wrote:
| a couple reasons why this is unlikely anytime soon. one
| is that the engineering processes between the designer
| and the fab are still too tightly coupled. some for good
| reason and some that they want to sell you engineering
| servives.
|
| the other is that the fab schedule is heavily laced with
| sales politics. getting a timely slot is largely a factor
| of how important a customer you are and none about
| scheduling work. they have as much work as they could
| ever want.
| withinboredom wrote:
| So, if I am hearing you correctly, someone starting this
| up would have all the customers they could ever want
| simply by being easy to use, well documented, and no
| sales bullshit?
| convolvatron wrote:
| if they just a had a few hundreds of billions lying
| around to prop up competitive fabs. absolutely!
| nick__m wrote:
| I am not an EE nor do I design chips but I think that the
| quality of your fab process and the usefulness of your
| blocks library would be more important success factors in
| acquiring customers than those you listed.
| bgnn wrote:
| EE chip designer here. this is 100% correct. just one
| point to add: quality of fab process as is also doesn't
| immediately matter. it's a matter of
| reputation/reliability. Intel for example is trying so
| hard to gain their reputation back. Fabs don't compromise
| theor quality for any customer to keep that reputation
| alive. it's incredibly hard to bring something new and
| disruptive by a new player. you need deep pockets (10s of
| billions to burn) and industry insiders to somewhat buy
| some reputation.
|
| only exception to this is China. it's slightly easier to
| do this there at the moment. through they often transfer
| TSMC heavy-weights to manage their fabs.
| pjc50 wrote:
| > all the customers they could ever want
|
| Again, the market for this is _tiny_. How many companies
| do you really think want a shuttle service?
| withinboredom wrote:
| haha, yeah, I have no desire to enter this space so I
| really haven't a clue. But I smell potential there; but
| it won't be me that takes it.
| bgnn wrote:
| check out Musesemi. There are a bunch of companies doing
| this as a service.
| jwagenet wrote:
| Also not a chipmaker, but my impression is silicon has
| tons of institutional knowledge you can't just find
| online and I imagine all the upstream vendors are going
| to be very similar to the fabs you are trying to replace.
| Unlike software, hardware can't be bootstrapped with a
| disruptive idea and the shirt in your back.
| bgnn wrote:
| no. someone with decades of experience bringing silicon
| to market maybe, but still no one would change their
| supply chain for ease of use. there's nothing easy in IC
| design, for good reason, and the industry learned to deal
| with it. what the industry values the most is
| reliability.
| pjc50 wrote:
| It's necessarily an interactive process. They will want
| an NDA (you generally can't get the fab "library" or even
| process information without this!). They'll want to do
| sales work on you. There's enough bits where they will
| want to check your work and understanding because it
| reflects badly on _them_ if the result doesn't work in a
| way which could be deemed their fault. A lot of this
| stuff already exists for PCB manufacturers and has very
| gradually been automated into a SaaS, but chip shuttle is
| a _much_ smaller market than PCBs and will remain that
| way.
|
| An example list of steps:
| https://www.usjpc.com/en/ourbusiness/shuttle.php
| nine_k wrote:
| About as soon as a SaaS self-service to order a piloted
| jet plane.
|
| Either you're really big and can put serious resources
| into R&D and production, or you can have a few toy-sized
| offerings for the lowest end that are only good for
| highly custom or testing purposes, or you are too small
| to care.
| jasonjayr wrote:
| https://tinytapeout.com/ <-- there is this project ...
| lmaothough12345 wrote:
| What is would you consider the rule of
| thumb/guideline/standard/considerations for a business
| needing a custom CPU?
|
| Like what would drive the cost of a custom chip being
| cheaper than adapting something more of the shelf?
| Pet_Ant wrote:
| > 180nm is potato quality - many many generations behind.
| So far behind it might actually be more expensive to get
| chips than at 110/65nm, although I'm only speculating here.
|
| I mean that is year 2000 level-tech. PlayStation 2/Pentium
| 3/AMD Duron/GameCube levels. That is not potato. You can
| definitely do things with it.
|
| https://en.wikipedia.org/wiki/180_nm_process
| amelius wrote:
| What EDA software do you need and how much does it cost?
| bgnn wrote:
| Normal prices are extremely high and depend on the tech
| node. A simple CPU development in something advanced like
| 5nm would probably require a license package for 30+
| engineers for 2 years or so. This would cost millions of
| $ per year. Depends how good you negotiate your prices.
| Some start-ups get 99% discount if they know a guy.
|
| The EDA is dominated by Synopsys, Cadence and Mentor
| Graphics. Each offer every tool but what I often see is a
| mix and match of tools from all three.
| JonChesterfield wrote:
| Optimistically tagging on here as it's a similar sort of
| question.
|
| Say one lone developer gets a bit carried away with verilog and
| ends up with a description for a chip. I know there's an odd lot
| style of thing where you can get your chip drawn on a wafer along
| with a load of other chips from other people. There's probably a
| way of getting someone who knows what they're doing to attach
| wires to it, wrap it in plastic or whatever else is involved in
| "packaging".
|
| Where does one get started with that, and what's the ballpark
| cost? I'm assuming a fair amount of the OP's $100k is SiFive
| labour, but I don't know how to guess whether a half dozen custom
| chips in some sort of packaging is of the order of 10s of dollars
| or 10s of thousands.
|
| (edit: I've done a lot of software near hardware and have a vague
| idea that uploading the data to tsmc was called "tape out" and
| involved quite a lot of money, but I also vaguely remember
| talking to someone at a conference who had chips made as a hobby
| so there are some pieces missing from my mental model)
| dfgs234 wrote:
| If you just want to put your verilog into an ASIC then it can
| be done fairly inexpensively these days.
|
| For example: https://efabless.com/chipignite $10K for 100
| packaged dies in QFN. Which is not totally out of hobby range
| (I've seen people spend way more on fixing up cars that have no
| business being fixed) and if you use their harness they'll
| solve most of the hard EE problems for you.
|
| But you might consider why you're making the IC. If it's for
| the experience, sure. But if it's to make a commercial product,
| there's a lot more to it. For example, what's your IO
| solution...
| JonChesterfield wrote:
| Nice example, thank you. I have no interest in making a
| commercial product but some motivation to learn what lies
| below the ISA. Like you say, that's cheaper than some more
| common hobbies. I work in the software side of semiconductor
| companies so it's a reasonable spin on professional
| development too.
|
| A friend recently discovered that PCBs can be ordered online
| for essentially zero cost and arrive in the mail and that
| surface mount soldering is an easy thing. Combined with a
| path for code to magic sand that's a whole world of dubious
| past times suddenly available.
| dfgs234 wrote:
| You might find this course helpful then. There is a huge
| amount of information you need to consume to make an IC so
| having it all organized for you is pretty valuable. It will
| save you many, many, hours. :)
|
| https://zerotoasiccourse.com
| wrs wrote:
| Wait'll you find out the same company that makes the PCBs
| will also source the parts and do the soldering for you, as
| well as 3D print the case -- all in quantity 2 and up! All
| for incredibly cheap, and 6-day turnaround to your (west
| coast US) door. It's a golden age for random hardware
| hacking. (Check out JLCPCB and PCBWay.)
| IshKebab wrote:
| If you just want to learn how CPUs are designed then get an
| FPGA. The process of running a chip on an FPGA is very
| similar to the process of getting a custom ASIC built.
| thebeardisred wrote:
| Thanks for mentioning e-fabless. When I saw $100k, the first
| thing I thought was "cool, now remove a zero". I love the
| capabilities the future is bringing.
| krallja wrote:
| https://tinytapeout.com/
| ganzuul wrote:
| Cool concept!
| dragontamer wrote:
| The secret is that 180nm nodes are so legacy that they have a
| ton of spare cycles for educational and apparently now
| hobbyists. Lots of various businesses are offering services now
| that sell the ancient 180nm node.
|
| Overall, the plan is much like OSHPark. You build a die that
| can be paired up with all of the other customers for a run. If
| say 300 wafers are made with 1000 different designs on it,
| everyone gets 300ish chips (before errors) and 1000 designers
| are happy.
|
| *Made up numbers of course. I'm not in the business.
| dfgs234 wrote:
| > The secret is that 180nm nodes are so legacy
|
| That's true but they keep upping the capabilities of what the
| designer can do at 180nm. Based on the wait times for my
| jobs, there's not a lot of spare cycles, at least at the
| foundries I use.
| dragontamer wrote:
| 180nm is declining as far as I'm aware.
|
| Its more likely that 180nm fabs are idling so much that
| they've made the decision to close. There's only so low
| that the prices can go before these businesses don't think
| its worth staying in business anymore.
|
| I've heard that over the long term, 28nm should
| theoretically be the "long term cost-efficient node". The
| 65nm and other nodes are all cheaper in practice because
| these factories are fully paid off by now.
|
| It was something about 300mm wafers and overall tooling
| being shared with 28nm with the latest nodes + overall
| investments. While 200mm likely will be shutdown over the
| long term (but 200mm wafers will remain the cheapest
| solution in the short term).
|
| So under these expectations, I'd say that 180nm, 65nm, and
| other old nodes will slowly shut down as everyone moves to
| the long-term most efficient node. Still, having the oldest
| nodes stay open for the educational / hobbyist /
| experimental R&D for some commerical companies makes sense.
| Especially since the wafers are smaller and thus overall
| runs can be smaller.
| jpm_sd wrote:
| I took a look at your blog[0]. You aren't going to need a custom
| CPU. You'll be much better off with something that's already in
| production, in the market, well-documented and well-tested. Also
| it sounds like you have a pretty steep learning curve ahead of
| you.
|
| [0] https://flyingcarcomputer.com/posts/a-new-personal-computer/
| corytheboyd wrote:
| I'd love an actual description of how this will change personal
| computing. The blog post is just a bunch of small technical
| decisions and opinions, doesn't mention anything about personal
| computing. Maybe they should build an OS variant instead? The
| home page blurb of "No AI. No cloud. No distractions" is
| already very attainable without inventing a new type of
| computer...
|
| Regardless, respect. Seems daunting, but will no doubt be a
| really cool project.
| svnt wrote:
| This is one of the kindest comments I have seen here.
| sircastor wrote:
| It's worth noting that if you're interested in making your own
| custom silicon, you can get it done quite inexpensively. It's not
| a fast process, but if you want to try your hand at building
| something that is all you, you can!
|
| This isn't want SiFive was doing - they're providing engineering
| expertise. Here you're allowed to put together all your own logic
| gates into... a thing.
|
| https://tinytapeout.com/
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