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Posted by Narishma 3 hours ago

A 3rd World Embedded Engineer Responds to "RISC-V They Should Have Known Better"(rvembedded.com)
197 points | 111 comments
ndiddy 1 hour ago|
I think he's kind of speaking past the original author. The original piece is basically about how the author doesn't think that RISC-V will take off outside embedded, because of some design decisions that lead to poor performance compared to ARM64 and because so much of the ISA being optional means that there's too much fragmentation to make binary distribution feasible. Meanwhile, this piece is mainly about how RISC-V is great for embedded because companies can build it into custom chips with specifically the functionality they need, and because of how cheap it is for low-end use cases since there's no license fees.

The only real point of contention I see between the two is that this piece goes on to talk about how it's a selling point that RISC-V can be used for both low-end 10 cent microcontrollers, and high-end multi-core processors running Linux. Personally I don't see the benefit of this since you're going to have to recompile your software anyway, and since all the RISC-V SBCs I'm aware of have significantly worse performance and efficiency than comparably priced ARM SBCs.

gertop 58 minutes ago||
> Personally I don't see the benefit of this since you're going to have to recompile your software anyway

The benefit is a unified toolchain. Make a chip, get the entire software toolchain for free.

In the past if you made your own chip you had to write your own assembler, compiler, debugger, etc. Many manufacturers forked gcc but of course it's still a lot of work and the license isn't great (for them, not the user).

This universal compiler toolchain is massive benefit for both the chip makers and the end user.

quotemstr 1 hour ago|||
Different RISC-V dialects might as well be as different from each other as English is from German. Sure, the cognates, family the resemblance, and common(-ish) alphabet make some things easier, but if you're shipping a manual, you still need to do it both in English and auf Deutsch unless you rely on machine translation.

So it is with the family of mutually incomprehensible ISAs called RISC-V.

Geof25 9 minutes ago||
Yeah I know this mess in PowerPC. There is IBM Power, there is MPC5xx ISA, there is VLE and and several other dialects. Some processors are doing those some doing others, some needs bit to signal if program runs VLE... just crazy chaos.
whateverboat 59 minutes ago||
The huge number of companies building RISC-V chips and really crazy optimizations that they are doing in all kinds of spaces are a very real counterweight to your notion.

And RISC-V is just starting here with shoestring design and fab budget. Wait till all engineering teams really adopt it like Tenstorrent and NextSilicon and so on.

yjftsjthsd-h 33 minutes ago|||
> The huge number of companies building RISC-V chips and really crazy optimizations that they are doing in all kinds of spaces are a very real counterweight to your notion.

I assume this is addressing

> and since all the RISC-V SBCs I'm aware of have significantly worse performance and efficiency than comparably priced ARM SBCs.

If so, could you point at specific SBCs that beat ARM SBC perf?

pixelesque 50 minutes ago|||
> really crazy optimizations that they are doing

Any examples of this?

camel-cdr 16 minutes ago|||
Here are a few random things I know of:

* Tenstorrent Ascalon has a neat optimization for certain LMUL>1 SIMD operations. LMUL=2 effectively unrolls the SIMD operation making it read two SIMD registers from every source and write two SIMD registers to the destination. There are however some instructions where LMUL=2 only needs to write to one registers, those are narrowing instructions (e.g. 64-bit to 32-bit truncation) and comparisons (which write to a LMUL=1 register with packed bits). When those SIMD instructions have to .vx form, which means one argument comes from a GPR, they now only need to write one SIMD register and need to read two SIMD registers. This matches what regular SIMD instructions need and because the silicon for the execution is much cheaper than register file ports, Ascalon can exexute these instructions in a single operation. So you can compare twice as many SIMD elements against a scalar, then you can against another SIMD register.

* Ventana (now under Qualcomm) talked a tiny bit about their fetch-block-optimizer and something that sounded like a L1i-trace cache. The fetch-block-optimizer would go to certain hot L1i entries and "optimize" them, with agressive instruction fusion including fusion of non-adjacent instructions.

* NextSilicon: Idk any details yet, but they said they handled RVC without increasing latency and that they've found a good solution for implement RVV and especially LMUL, which is a challange in out-of-order designs.

* OpenXiangShan: The fastes open-source CPU, is working on doing 2-ahead instruction fetch (the thing Zen5 added).

Now that being said, Ventana was bought by Qualcomm, we know the RISC-V team is still alive, but who knows if we'll ever see anything from that outside of Qualcomm?

The Tenstorrent Ascalon devboard is way behind schedule and on 12nm TSMC instead of a 4nm node the processor was designed for and is now supposed to clock at 1.38GHz. Though I think the delay has more to do with TT management problems then with the actual design.

While the scalar part of OpenXiangShan looks really good, the RVV imolementation is currently basically unusable. They want to have fix for the problems until the end of the year, but we'll have to see.

PunchyHamster 33 minutes ago|||
There aren't ones that wouldn't be served better by ARM

The improvement is entirely "we don't have to pay ARM"

kelnos 22 minutes ago||
I don't really understand the author's conclusions about cost and shipping, and how RISC-V is cheaper and more accessible to people outside the US and Europe. He first talks about how getting $1 worth of chips can cost $60-$200 in shipping for him due to his location... but then by the end claims that RISC-V gives him "an architecture that arrives in my country at ten cents a part".

I don't get how both things can be true. The cost to ship something to Trinidad and Tobago has nothing to do with whether it's ARM or RISC-V; shipping the same weight of either kind of chips should cost exactly the same amount. Yes, maybe the chip cost itself of a particular ARM-based model is $0.15 while the equivalent RISC-V chip costs $0.10, but if the issue (for him and other people who live outside US/Europe) is that shipping costs are orders of magnitude more expensive than the thing being shipped, that chip-cost difference becomes irrelevant.

I think he does make a great point about how fragmentation does give you better optionality: ARM is sort of like cable TV where you have a small number of product categories that each bundle a particular set of features, whereas with RISC-V you design something bespoke that does exactly what you need and nothing more. But again, this isn't going to affect shipping costs.

vlovich123 1 hour ago||
He says:

> From that position, the difference between a ten cent part and a one dollar part is not a rounding error and it is not a detail you get to wave past on the way to the interesting discussion about encodings

Yet earlier:

> I pay anywhere from US $60 to US $200 to ship one dollar chips that people everywhere else get free shipping on

Seems to me that the difference between a 10c chip and a $1 chip are a rounding error when the shipping cost dominates so much?

cupantae 1 hour ago|
I’d really like an explanation here if the author is reading. And how does shipping cost scale with quantity? Can you get that to be small per unit on big orders?
HawtAds 2 hours ago||
I love the article, it's a breath of fresh air compared to the usual bay area centric takes. However there's just one issue:

> The students I want to teach are in the same position, and so are the ones in Nigeria and Bangladesh

It does not take $60 to ship small sub $1 chips from Asia to Nigeria/Bangladesh. These two countries are all on global trade routes (both supply and demand) and the expensive last mile delivery costs are fairly low there too.

bigcat12345678 1 hour ago||
This is a bay area centric take on a non bay area centric take.

The typical bay area centric take has the following vibe:

1. I am among the group of most open minded people

2. I admit mistakes, but I don't change my view, that means I may make the same mistakes next time on a different concrete cases

3. Morally I am among the least corrupted

4. I work for the moderately morally questionable firms with nice paychecks, but my moral views are not tainted a bit

5. I never think on the other's perspectives

tekla 1 hour ago||
As exemplified in the following series of essays

https://www.astralcodexten.com/p/the-foothills-of-bay-area-h...

Avicebron 1 hour ago|||
This one was more self-aware than others. But we all know the demon voice of San Francisco sounds like a shoggoth trained on LessWrong.
msdz 1 hour ago|||
Thank you so much for sharing these. I just laughed my ass off a bunch, and I’ve only yet read this one latest post in the series.

My favorite bit, I think (along with the running gag of the constant use cases/connections that somehow pop up for Epstart’s founder):

> “Would you like to hear more about how copying AI tics helps me keep conversations going?”

> “Uh, sure - wait! No!” You break off and turn around as fast as you can.

If the other entries in the series are anywhere near as good, I’ll have some reading to do now.

TruffleLabs 2 hours ago|||
Is this comment on shipping costs from Asia to Nigeria/Bangladesh based on your experience? If there is a less expensive way then share the approach to help others :)
em-bee 2 hours ago|||
i don't know how trustworthy rateships.com is, but according to them shipping costs to nigeria and trinidad are similar. and as for the last mile, the cost probably goes up because local shipping is rather unsafe (higher rate of theft of packages).
notenlish 1 hour ago|||
It could be bureocratic barriers. For example, Turkey recently changed importing laws so that anything(even stuff sent to you for free) from outside the country is subject to tariffs & import costs. Importing a cheap component worth 1$ costs like 300$.
spacechild1 1 hour ago|||
> from Asia to Nigeria/Bangladesh.

Bangladesh is a country in Asia...

farlight 1 hour ago|||
I am in Asia, this means nothing, it's the largest continent on earth. I don't pay as much for shipping as the author does, but his struggles are nevertheless relatable: most sellers refuse to ship here, most of those who do want dozens and dozens of dollars for it, and some (few, usually Chinese) sellers save the situation from being completely hopeless.
pooper 1 hour ago||||
In my experience, people in the United States often (incorrectly) short hand East Asia as Asia just like the people in the city of New York will often (correctly) short hand New York City as New York.
chronic7403 1 hour ago|||
> In my experience, people in the United States often (incorrectly) short hand East Asia as Asia just like the people in the city of New York will often (correctly) short hand New York City as New York.

In my experience, the only demographic who complains about “Asia = east Asia” are people from South Asia, aka Indians/desis

graemep 5 minutes ago|||
People from South Asia are not "aka Indians". There are other countries.
andybak 1 hour ago||||
Ironically (for my generation in the UK at least) "Asian" meant "South Asian" and for a long time we didn't have a useful shorthand for "all parts of Asia"
Conan_Kudo 1 hour ago|||
We aren't the only ones, but we are the loudest about it, because erasure sucks.
stavros 1 hour ago||
Don't get me started about Macedonia.
bonoboTP 1 hour ago||||
It's an interesting evolution given that Asia as a term started out meaning just the westernmost tip of current-Asia, ie Western Anatolia.
elashri 26 minutes ago||
When the term started out, There was nothing called United States (As a country or its current culture/s). And I am not sure if this happens outside the US anyway.
tyre 1 hour ago|||
Slight correction, people in NY refer to it as “The City” and people in NYC say the same, but specifically mean Manhattan.
cyberclimb 1 hour ago||||
I don't think they are necessarily asserting otherwise
spacechild1 1 hour ago|||
So what does it mean to ship from Asia to Bangladesh? Do you ship from India, Iran or Indonesia? Or just within Bangladesh? :)
articulatepang 35 minutes ago||
In the context of microcontrollers and electronics, the likeliest intended meaning was shipping from China, South Korea, Taiwan and perhaps Japan, because that’s where the bulk of the fabs are.
Ar-Curunir 1 hour ago|||
Shipping from Asia to Asia doesn’t make much sense
bigfatkitten 14 minutes ago|||
Hey, Asia’s not that big. If you’re in Bangladesh, you can simply walk to the electronics store in Japan.
cwillu 1 hour ago|||
Asia is a pretty big place
k_roy 1 hour ago||
Compared to a banana?
BigTTYGothGF 1 hour ago|||
So is Ireland.
gaius_baltar 1 hour ago|||
> It does not take $60 to ship small sub $1 chips from Asia to Nigeria/Bangladesh

So don't even try to find how expensive is bring these to Brazil. Even the $5 orders from JLCPCB become infeasible for hobbyists here due to all the roadblocks.

alephnerd 2 hours ago|||
> it's a breath of fresh air compared to the usual bay area centric takes...

HN hasn't been Bay Area centric in years. Honestly, most comments and usership on the platform seems to now align with SWE culture in DACH and CEE.

Presumed RISC-V hate is a perfect example of that - the UCs and CSUs have been using RISC-V in their curriculum since the 2010s becuase Patterson is faculty at Cal and most CompArch courses in both systems have been using RISC-V as a result because 61a/b/c are often used as the benchmark curricula wise. An entire generation of Californian computer engineers have been RISC-V fluent as a result.

The hivemind assumption that HN's user base is "venture capital", "tech bro", "founders", and "Silicon Valley" is around 5 years out of date.

Anecdotally, the vast majority of younger (below 30) founders, engineers, VCs, and builders in the Bay have either not heard of HN or quit it within weeks due to toxicity.

greyb 2 hours ago|||
>HN hasn't been Bay Area centric in years. Honestly, most comments and usership on the platform seems to now align with DACH.

I honestly do not get this at all. HN remains very US-centric to me, and especially centric to the mindshare of the Bay Area's IRL conversations, and apart from some takes on tech rights, does not really remind me of my experience in DACH.

weinzierl 1 hour ago|||
As someone from the DACH region I very much agree with this. I don't see a shift from typical US opinions to opinions often held in the DACH region. Not at all.
r3trohack3r 1 hour ago||||
> HN hasn't been Bay Area centric in years.

>> HN remains very US-centric

Bay Area != US

The Bay Area is its own microcosm of culture and philosophy that diverges significantly from much of the US.

Not making a statement on how prevalent either are on HN, but Bay Area is very much not equivalent to the US.

MBCook 1 hour ago||
As an American, it’s extremely Silicon Valley centric, at least in mindset.

Extremely. The valley/startup lens is absolutely the dominant one.

alephnerd 2 hours ago|||
> I honestly do not get this at all. HN remains very US-centric to me, and apart from some takes on tech rights, does not really remind me of my experience in DACH.

The majority of HN's usership, posting, and comment activity occurs during peak EU work hours (3am-9am), stylistic patterns that are common for German-, French, and Polish-native speakers are increasingly prominent (eg. periods and spaces instead of commas in numbers, spacing between quotation marks and words, failing to use context clues to infer timezone), and the fact that IRL conversation topics in the Bay Area tech scene are entirely different from those on HN shows a massive divergence in userbase.

HN "Who wants to get hired" threads are a good example of that as well.

I'd recommend deep diving in the HN scrape dataset on HuggingFace [0]. The site has diverged heavily compared to 2018 or 2012.

[0] - https://huggingface.co/datasets/open-index/hacker-news

Avicebron 2 hours ago|||
How would you say the "IRL conversation topics in the Bay Area tech scene" diverge from HN?
AlotOfReading 2 minutes ago||
Haven't seen anyone sending partiful invites here.
snowpid 1 hour ago|||
While I appreciated your source 1.) I doubt 99% of Europeans work during 3am - 9am 2.) At least there can be other reasons: 2a.) EU times and African times are basically the same and Africa has a huge population. 2b.) India is closer timewise to EU/African time zones 2c.) What are about posts afterworks?

" RL conversation topics in the Bay Area tech scene are entirely different from those on HN shows a massive divergence in userbase. " Any proof?

kelnos 15 minutes ago||
I assume the 3am-9am figure was in US Pacific time, in order to emphasize the difference from the working hours of people on the US west coast.
orangeboats 2 hours ago||||
Non-American here... what is DACH?
greyb 2 hours ago|||
It is Germany, Austria, Switzerland.
orangeboats 2 hours ago|||
Thanks! I must admit this is the first time I have heard of the acronym.
Tomte 2 hours ago|||
Based on https://en.wikipedia.org/wiki/International_vehicle_registra...
slater 2 hours ago|||
Germany, Austria, Switzerland (D, A, CH)
em-bee 15 minutes ago||
D, A and CH are the international vehicle registration codes for those countries among other things. and "dach" as a word means "roof", which makes it memorable. some more fun facts here: https://en.wikipedia.org/wiki/Geographical_distribution_of_G...
snowpid 1 hour ago||||
" HN hasn't been Bay Area centric in years. Honestly, most comments and usership on the platform seems to now align with DACH and CEE. "

I like to encounter discussions about German digital health system or the German start up system or neo2. I've never seen them so I doubt it.

Also almost no debates about Polish stuff (Hello neigbours!)

GPerson 1 hour ago||||
How is it not tech bro centric when every third thread is about some new feature of a random Anthropic product?
handwarmers 2 hours ago||||
the fact that this comment is getting downvoted into oblivion instead of discussed is poignant enough.

fwiw, my experience is similar. hn has not been about startups, vc funding, or anything in that space for quite a while.

to paraphrase a classic, this place is like a memory of the forum we used to love, and the memory is fading.

bigbadfeline 1 hour ago||
> this place is like a memory of the forum we used to love, and the memory is fading.

Well, this place (wherever you are) is like a memory of the world we used to love, and the memory is fading... Definitely true too.

You can't expect a place tightly connected to a changing world to stay the same.

jdw64 1 hour ago|||
[dead]
jacquesm 1 hour ago||
So, you are calling the author a liar?
kazinator 40 minutes ago||
> He derives the case for the chip and then spends the rest of the article annoyed that the chip exists. This is almost satirical.

His criticisms are entirely valid, because why can't the the thing that has a free spec and will likely dominate that space ... also be good too? Can't we have all the nice things?

ksec 1 hour ago||
I don't think the Author disagree with what the original article wrote. If anything everything he said seems to reassert what the original article intended to state.

And while things has died down a lot in the past few years, there is a reason why I wrote the line.

"You do not criticise The Rusted Holy Grail and the Riscy Silver Bullet."

Sha1rholder 2 hours ago||
Nice read!

Though it feels a bit strange that "I have exceeded the allowed number of requests. (500 times)" when I first clicked the article and I'm pretty sure I don't share the ip of my self-hosted VPN with anyone.

tclancy 2 hours ago||
I think it’s telling the site owner, not us.
Animats 39 minutes ago||
I got that too and couldn't read the site.
gregsadetsky 1 hour ago||
Working archived copy - https://archive.is/9FaRC
syncsynchalt 1 hour ago|
Is archive.is still a malicious site that DDOS's finnish security bloggers or has that been sorted?
b40d-48b2-979e 15 minutes ago||
Nope, that is still them.
egypturnash 27 minutes ago||
Rate Limit Exceeded Too Many Requests

You have exceeded the allowed number of requests. Your Requests: 500. Request Limit: 500 per minute. Tip: Please wait 60 seconds before trying again.

A 3rd World Embedded Engineer Learns About Caching Generated HTML The Hard Way.

https://archive.md/9FaRC

avmich 2 hours ago|
To me it feels like the difference in positions is "this could be made better" vs. "but this is already so much better than before". Both are right.

Maybe I'm missing something important so far...

ipdashc 1 hour ago||
I was thinking the same. RISC-V is certainly impressive and I'm glad we have it, but the original article isn't wrong in its complaints either.

It definitely could have gone with a less abrasive tone (as entertaining as it is), so it's no wonder it's getting some pushback.

thayne 57 minutes ago|||
Maybe. I'm not sure if the original author's intent was to say how risc-v could be better or to say it is bad and people should use other (proprietary) ISAs instead.
IshKebab 2 hours ago||
Yeah the complaints in the original article are valid, but it's like complaints about Android or iOS. There are plenty of valid complaints against either, but neither is strictly better than the other.
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