DIY 256-Core RISC-V super computer 

I think your decision to not put everything on one big shared bus was the smart approach. Each input pin on the bus has a small amount of parasitic capacitance, which increases bus loading and requires additional drive current from the output pin driving the bus. That increases dI/dt which means more radiative EMI and crosstalk, and distorts the edges. This is less of a problem with an open drain setup, but still causes slower edge transitions and ringing. The long traces will have a lot of inductance which, left undamped, also tends to cause a lot of ringing. Longer traces also mean you're getting to the point where you're having to model them as transmission lines, since the Nyquist frequency of the design is set by the rise/fall time (not the clock!) and that's very fast on modern ICs - it's pretty common to see frequency components in the 300-800MHz range during transitions, so if you're running traces further than about 9cm you can no longer treat them as lumped lines. Once you get to this sort of scale you typically want to be using bus redrivers to break the bus up into smaller segments to avoid SI/EMI problems. If you start finding that you have SI issues once you add all the boards, two things you can do are reducing the pullup resistor value and adding a small resistor in series with each IO line. Right now with 5.1kΩ pullups you've got that classic sharkfin shaped clock, where the pullup resistor takes a while to overcome all the parasitic capacitance on the board. You can speed that rising edge up by reducing that pullup resistance - bodging a second 5.1kΩ resistor on top will do that. The falling edge is very fast because the IO pins are actively pulling the bus to ground. This causes big dI/dt spikes at the falling edge, while all that charge stored in the parasitic capacitances rushes through the low impedance path created by the active low-side FET. You can moderate that dI/dt with a small value resistor (e.g. 22Ω) in series with each of the IOs, so the bus is still strongly pulled down but the current isn't controlled only by the Rds(on) of the low-side FET in the IO. Since you've already spun the boards this might be kinda tricky to add - maybe something for a rev2/3? :)

Dude - use a foot-operated vacuum pen - much quicker & easier than tweezers!

Makes me wish I'd done electrical engineering at university. This level of dev is beyond my capability of simple analog electronics, I'm like a monkey with a spanner. Not enough time in the day now to reskill but your work is inspiring and why I'm subscribed.

I love the random clock variations on the blink sketch. Fun source lf entropy.

So awesome. IMO Fiasco would be a cool code name for a project or chip.

At 10 pins free per 48mhz cpu, you could connect 20,040 leds (or 6 million if they are combined). Enough to make a small terminal screen...or play bad apple. With each pin handling 90 leds at 48Mhz, this thing would push pixels like a monster. Just need the timing to be perfect.....

Not sure if you've done this already, but it might make sense for you to have a seperate "subnet" for each blade and then only send transmitted data on the inter-blade bus if the destination is outside of that subnet.

Ok, but can it run Crisis?

Watching your pick and place makes me want to both go into electronics and stay the heck away from it.

Can it run Doom?

I am a software person and I built cards with my electronic partner 15 years ago that each card has three microchip processors that communicate with each other on the card in fast serial communication on pullup lines. These cards communicated with other similar cards for ranges of 10 km on a pair of cords that also transferred the energy for the needs of agriculture in the field.

Ever heard of the "transputer", a 1980s commercial computer made of a collection of thousands of tiny weak processors working in parrel for advanced scientific tasks. Your cluster reminds me of it. Retrobytes channel made a video on it several months ago.

wow, this is incredible to see the idea from start. You're awesome!

first ime ive seen tape and tray of parts being used, kudos. i did inkdot for a year because i loved the simplicity and focus it required. they moved me to pin refurbishing when they found out i could do it easily

I love it when blink goes out of sync... it looks like one of Big Clive's "supercomputers" except it really is a supercomputer!

As always, an amazing project. The funky music for hand SMD assembly *almost* made it look enjoyable 😂

Your message collision scheme is remarkably similar to how CAN. works. It seems you've independently discovered an excellent system. very impressive.

Wow just discovered. Awesome. Can't wait for the next!!

Amazing work, what a project! 😮👍

CSMA/CD reinvented :)

Many kudos for attempting such a "mega-project". No pain no gain...

Cool project, thanks for sharing.

That is a lot of CPU power for some random blinking LEDs :)

This is the coolest thing I've seen in a while!

You're going to run Game of Life on that thing, aren't you?

I know people who would go over the edge for your random parts placement :) "All values of similar resistors have to face the same directions"... LOL. Nice one. Wish I had more time to join the livestreams again ...

I would use an active pullup (constant current source) on the bus with so many devices on the bus. It could be a current mirror with two P MOSFET transistors (e.g. BSS84). With 5 mA current, it would probably speed up the communications a lot.

Amazing video! you are teaching a lot of stuff with this.

that's going to be fun to program

this is nuts! , i love it!

I don’t know what it is, but I love it! More!

Awesome work 😮

Heck of a great project! And custom CDMA!

I have to admit, watching them go out of sync is beautiful. Am I weird to like that more than synchronized blinking?

This is so awesome!

Ein Jahr jeden Tag auf neue warten hat sich gelohnt 🥹🥹

This project reminded me about both the game of life automaton, KISS principle and CD part of CSMA/CD.

i just discover your channel an io immediately subscrtibed. this project mesmerize me. keep on!

A true work of art! My hats off to you! 🍻

"...actually 273 but okay" is the best subtitle for a video in the history of the platform.

Need more!

sounds insane in performance, but actually would be roughly equal to 4 cores running at just over 3ghz due to the low clockspeed. that said it does show it is possible, and if this works it will also work with much faster risk-v chips. actually in some arm architectures the cores where designed to be kind of used like this so you could just keep scaling them, there was actually some 1000core arm cpu somewhere around 2013 or such, sadly never took of since back then mulithreading didn't really practically exist yet, as in that basically no softwares used it, and that things like handling large amounts of data at once wheren't a thing yet. that said, risc-v is opensource, so it means it should be possible to actually make a risc-v cpu which directly combines tons of cores. if you plan to make something like that I do have a better way for you to try out than using a single bus(or a few busses) since using busses like that can work but can have problems, I roughly designed a new experimental way of doing such multichip communication for the raspberry pi foundation some years ago, actually was to try and get them to make a board with way more cores. but essentially it is a method giving quite some bandwith but also large buffering and chips being able to get the data when they are ready instead of needing to accept it directly, that said, in some cases direct busses might be more usefull, luckily in a full cpu design you can make many more busses, both have advantages and weaknesses depending on the loads.

You are very close to the original Ethernet CSMA/CD protocol. The XOR checksum has the problem that two colliders can cancel eachother - two single bit errors could result in a correct checksum - making a packet "appear" good. As such Ethernet uses a CRC. Further, if you detect a collision you "jam" the whole packet with alternating ones and zeros to really mess it up and then do your randomized backoff. What you will find, and you are not the first, is that as you scale the collisions will increase and the bandwidth will be insufficient. The cores will be data starved. This was the case with the Intel MIC's (Knight's Corner). They used PCI-E but the issue is the same, multidrop and star topologies oversubscribe easily. You will note datacenters (home of enormous clusters) used leaf spine (and other) interconnects to mitigate this. But fun none the less. So you have a huge number of course - what will you do with it? What would others in the comments run?

8:36 Holy rise time Batman! The Signal Integrity engineer just started breaking out in a cold sweat

Great stuff

Thats HUGE!!

after 2 minutes you already deserve a like!

just discovered your channel and this is super cool! what was your career path that got you into electronics? thanks!

Game of Life; Each Cell (group) has a finite time to check for- Food, Friend or Foe in adjacent blocks. Movement is turn based. Food, a limited, randomly placed resource, extends (life) up to 10 turns. Finding a Friend, adds a chance of 1-2 new Cells each turn. Each Foe can remove 1 adjacent Cell (not of its group) per turn, adding a chance for their group to grow next turn. *time is finite* for all Cells. Friend, Food or Foe. Meaning- the simulation ends, and you get to see a nice pattern of what groups fizzled, which ones flourished.

GAME OF LIFE on this would be insaine

Wow that's insane

So you are the guy that created the brain of skynet! I knew it!

You may be nuts, but that's much of the fun of watching. This project is a delightful sprawl, full of potential and hurdles. What do you want it to become, beyond the LED art? I mean, is there a target functionality or is the journey the goal? Well, I guess we'll find out.

crazy! in a good way!

The blink looked like game of life 😂

would be really cool to see this do something like a phone or computer software benchmark... with the lights it would be very satisfying... knowing the computer is actually computing... do the same for the hd/ssd and gpu 🤓🤓🤓 actual functional led display / rgb lighting

If you send a considerable amount of broadcast it makes sense to have a bit after the source address which is only set if it's a broadcast. So you can skip the target address completely. This only makes sense if you send a lot of broadcast messages, as every unicast message is then 1 bit longer

Really nice project. What are you using for the top view shots? 4:39

What an epic project! Subscribed Probably dumb question, but could the collision detection be replaced by a queueing system where an mcu can request the bus then get serviced fifo? Maybe that would be slower. Would be cool to see a map-reduce algorithm running on this beast.

Nice!

You could use the now free command pin to sync all the clocks together

5:18 > We can hear you laughing. I like your enthusiasm

😅 This is a kind of projects I really like watching, but I have a question, what can It really do beside some basic stuffs, anything like computing with a lot of cores ( that may be too hard 😮 ). In my opinion, this is an interesting project I love. Thank you for making the video, hope you have a great day 🎉🎉🎉

Very interesting and good job, but what's the next step?

very gud 👍

You can also add in a small fpga to make the to run or manage the cluster?

I think this is an amazing achievement. I would love to see you demonstrate its speed with some "sha-1"cracking or comparison testing against a raspberry pi 5 and a mid range PC with a long duration 24hr minimum to see how far 17Ghz can go I a day

3:30 LumenPnP when? My hand and eyes hurt just watching all that placement! ( I probably just have a low tolerance though lol)

this is really incredible. i'd love to see a collab between you and @beneater !!! Really great work.

I've got two questions: 1) for what could this be used for? 2) for the waiting time after a collision, couldn't you use the ID itself as a delay? Or maybe force them to report in order, maybe using a master or calling the next one in line

Did you just create a pretty good random number generator with those blinking leds? Looks much cooler than those lava lamps

You may want to decrease the resistance on your clock line. A slow rise time can cause one of the processors to miss a clock and become out of sync with the host.

Pretty project, thanks for sharing

An absolutely awesome project with great prospects and the limitation is the users imagination. however, I have 2 questions: 1. can it run doom? 2. in chat language was the code written? was it C/C++>

he's gone mad!

I have been planning to do this with sg2002s.

nice project, but i have one question. i want to try this chip CH32V003 but can i use other swd debugger or it need to be e-link debugger?

I would mine so many moneroj with this

let's game on it! :D

Hi, Is there a video on the tool chain for this uC ? Cheers !

Nuts!

Would you he able to upload those first streams in which you made the cluster and the protocol? It's not on twitch nor RU-vid...

What might be some of the use cases for the Megacluster?

how is software development with the ch32 ic? i have been thinking of trying them out, but the "sdk" (or examples) looked really scary...

Your collision detection is very similar if not the same as CAN Bus collision detection (I need to check but I believe it’s at least close)

if the collision detection is waiting a random time using the ID as the seed so they're always different, why not just use the ID as the amount of wait time directly?

Despite missing half of the explanation bcs I have no idea what the used terms means, I nevertheless found everything fascinating. For me, its like our modern day version of an art painting. Can u tell me which kind of university degree/knowledge/skills are necessary for such project? And good job! 👍

You are integrating systems for the s100 bus.

super..., so what is it for? what you can implement on it?

Nice e-waste ! Congrats !

I would love to see a super cluster with the cluster and a 2040 I/O chip?

I don't even know what to say. I'm jealous of you.

Why fiasco? I thünk there is hard work and clever work arounds in this project. Keep your head up!

I'm curious, is there a benefit to this type of bus communication versus an established protocol like ethernet, i2c, etc. Is it just simplicity or speed? Im a student and havent studied this area yet.

What’s the music playing during assembly at 4:13?

Why not CAN Bus? It already has a good data arbitration mechanism and checksum, no need to reinvent the wheel :)

0:50 imagine the reveal of an ai being sentient by the blinking lights getting faster and faster and then it stops, and just starts showing text?

Those timelapses a true Luni Pick & Place

Could u check the flux link? it also refers to the syringe page! thx!!

epic gaming