From a performance standpoint we know building a homebrew Raspberry Pi cluster doesn’t make a lot of sense, as even a fairly run of the mill desktop x86 machine is sure to run circles around it. That said, there’s an argument to be made that rigging up a dozen little Linux boards gives you a compact and affordable playground to experiment with things like parallel computing and load balancing. Is it a perfect argument? Not really. But if you’re anything like us, the whole thing starts making a lot more sense when you realize your cluster of Pi Zeros can be built to look like the iconic Cray-1 supercomputer.
This clever 3D printed enclosure comes from [Kevin McAleer], who says he was looking to learn more about deploying software using Ansible, Docker, Flask, and other modern frameworks with fancy sounding names. After somehow managing to purchase a dozen Raspberry Pi Zero 2s, he needed a way to keep them all in a tidy package. Beyond looking fantastically cool, the symmetrical design of the Cray-1 allowed him to design his miniature version in such a way that each individual wedge is made up of the same identical set of 3D printed parts.
In the video after the break, [Kevin] explains some of the variations the design went through. We appreciate his initial goal of making it so you didn’t need any additional hardware to assemble the thing, but in the end you’ll need to pick up some M2.5 standoffs and matching screws if you want to build one yourself. We particularly like how you can hide all the USB power cables inside the lower “cushion” area with the help of some 90-degree cables, leaving the center core open.
You’ve probably heard it said that clustering a bunch of Raspberry Pis up to make a “supercomputer” doesn’t make much sense, as even a middle-of-the-road desktop could blow it away in terms of performance. While that may be true, the reason most people make Pi clusters isn’t for raw power, it’s so they can build experience with parallel computing without breaking the bank.
So while there was probably a “better” way to produce the Mandelbrot video seen below, creator [Michael Kohn] still learned a lot about putting together a robust parallel processing environment using industry standard tools like Kubernetes and Docker. Luckily for us, he was kind enough to document the whole process for anyone else who might be interested in following in his footsteps. Whatever your parallel task is, and whatever platform it happens to be running on, some of the notes here are likely to help you get it going.
[Paul Brown] wants to take advantage of off-site server colocation services. But the providers within [Paul]’s region typically place a limit of 1A @ 120V on each server. Rather than search out commercial low-power solutions, [Paul] embraced the hacker spirit and built his own server from five Raspberry Pi 4b single board computers.
The task involves a little bit more than just mounting five Pi4s in a chassis and calling it done. There is an Ethernet switch connecting all the modules to the network, and each Pi has a comparatively bulky SSD drive + enclosure attached. By far the most annoying part of the assembly is the power supply and distribution cabling, which is further complicated by remote controlled power switching relays (one of the computers is dedicated to power management and can shut the other four modules on and off).
Even if you’re not planning on building your own server, check out the thoroughly documented assembly process and parts list — we particularly liked the USB connector to screw terminal breakout connector that he’s using for power distribution. For all the detailed information, assembly instructions and photos, we think a top-level block diagram / interconnection drawing would be very helpful for anyone trying to understand or replicate this project.
There are a lot of connections in this box, and the final result has a messy look-and-feel. But in fairness to [Paul]’s craftsmanship, there aren’t many other ways to hook everything together given the Raspberry Pi form-factor. Maybe a large and costly PCB or using CM4 modules instead of Raspberry Pi boards could help with cable management? In the end, [Paul] reckons he shelled out about $800 for this unit. He compares this expense with some commercial options in his writeup, which shows there are some cheaper and more powerful solutions. But while it may be cheaper to buy, we understand that strong urge to roll your own.
If you ever need to cluster up to 14 Raspberry Pis and an equal number of 2.5 inch hard drives, you might want to look at the Raspberry Pi Server Mark III case from [Ivan Kuleshov]. The original Mark I design came from Thingiverse, but the Mark III is a complete redesign.
The redesign allows for more boards along with a reduction in the number of parts. That takes less plastic and less time to print. The design is also modular, so there should be new components in the future.
Parallel computing is a fair complex subject, and something many of us only have limited hands-on experience with. But breaking up tasks into smaller chunks and shuffling them around between different processors, or even entirely different computers, is arguably the future of software development. Looking to get ahead of the game, many people put together their own affordable home clusters to help them learn the ropes.
As part of his work with decentralized cryptocurrency, [Jay Doscher] recently found himself in need of a small research cluster. He determined that the Raspberry Pi 4 would give him the best bang for his buck, so he started work on a small self-contained cluster that could handle four of the single board computers. As we’ve come to expect given his existing body of work, the final result is compact, elegant, and well documented for anyone wishing to follow in his footsteps.
Outwardly the cluster looks quite a bit like the Mil-Plastic that he developed a few months back, complete with the same ten inch Pimoroni IPS LCD. But the internal design of the 3D printed case has been adjusted to fit four Pis with a unique staggered mounting arrangement that makes a unit considerably more compact than others we’ve seen in the past. In fact, even if you didn’t want to build the whole Cluster Deck as [Jay] calls it, just printing out the “core” itself would be a great way to put together a tidy Pi cluster for your own experimentation.
Thanks to the Power over Ethernet HAT, [Jay] only needed to run a short Ethernet cable between each Pi and the TP-Link five port switch. This largely eliminates the tangle of wires we usually associate with these little Pi clusters, which not only looks a lot cleaner, but makes it easier for the dual Noctua 80 mm to get cool air circulated inside the enclosure. Ultimately, the final product doesn’t really look like a cluster of Raspberry Pis at all. But then, we imagine that was sort of the point.
Many readers will have had their first taste of experimentation with cluster computing through the medium of the Raspberry Pi. The diminutive Linux capable boards can easily be hooked up as a group via a network hub, and given the right software become a whole that is greater than the sum of its parts. None of us will however have reached the heights of the Raspberry Pi cluster shown by Oracle at their Oracle OpenWorld conference, a mighty rack packing a cluster of no less than 1060 Pi 3 B+ boards. This machine is touted as a supercomputer and it’s worthy of the name, though perhaps it’s not in the same class as the elite in that field.
Getting that number of individual 3Bs into a human-sized rack is no easy feat, and they have gone for custom 3D-printed racks to hold the boards. PoE would have resulted in too much heat dissipation, so instead they use USB power from an array of large multi-way USB power supplies. A set of switches provide the networking, and a conventional server sits in the middle to provide storage and network booting.
It’s certainly a cool way to wow the crowds at a conference, but we’re unsure whether it delivers the best bang for your supercomputing buck or whether it’s more useful as a large room heater. Meanwhile you can take a look at a few more modest Pi clusters, with unusual operating systems, or slightly more adherence to convention.
We see a lot of weird and esoteric stuff here at Hackaday, but even by our standards, Bell Lab’s Plan 9 operating system is an oddball. Named after the science fiction film Plan 9 from Outer Space, it was designed to extend the UNIX “everything is a file” mentality to the network. It envisioned a future where utilizing the resources of another computer would be as easy as copying a file. But as desktop computers got more powerful the idea seemed less appealing, and ultimately traditional operating systems won out. Of course, that doesn’t mean you still can’t play around with it.
Logically to make use of a distributed operating system you really need something to distribute it on, but as [Andrew Back] shows, today that’s not nearly the challenge it would have been back then. Using the Raspberry Pi, he builds a four-node Plan 9 cluster that’s not only an excellent way to explore this experimental operating system, but looks cool sitting on your desk. Even if you’re not interested in drinking the Bell Lab’s Kool-Aid circa 1992, his slick desktop cluster design would work just as well for getting your feet wet with modern-day distributed software stacks.
The enclosure for the cluster is built from laser cut acrylic panels which are then folded into shape with a hot wire bending machine. That might seem like a tall order for the home hacker, but we’ve covered DIY acrylic benders in the past, and the process is surprisingly simple. Granted you’ll still need to get access to a beefy laser cutter, but that’s not too hard anymore if you’ve got a hackerspace nearby.
[Andrew] uses short extension cables and female panel mount connectors to keep everything tidy, and with the addition of some internal LED lighting the final product really does look like a desktop computer from a far more fashionable future. Combined with the minimalist keyboard, the whole setup wouldn’t look out of place on the set of a science fiction movie. Perhaps that’s fitting, giving Bell Lab’s futuristic goals for Plan 9.