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GCHQ Builds a Raspberry Pi Super Computer Cluster
mikejuk writes GCHQ, the UK equivalent of the NSA, has created a 66 Raspberry Pi cluster called the Bramble for "educational" purposes. What educational purposes isn't exactly clear but you do associate super computers with spooks and spies. It seems that there was an internal competition to invent something and three, unnamed, GCHQ technologists decided that other Pi clusters were too ad-hoc. They set themselves the target of creating a cluster that could be reproduced as a standard architecture to create a commodity cluster. The basic unit of the cluster is a set of eight networked Pis, called an "OctaPi". Each OctaPi can be used standalone or hooked up to make a bigger cluster. In the case of the Bramble a total of eight OctaPis makes the cluster 64 processors strong. In addition there are two head control nodes, which couple the cluster to the outside world. Each head node has one Pi, a wired and WiFi connection, realtime clock, a touch screen and a camera. This is where the story becomes really interesting. Rather than just adopt a standard cluster application like Hadoop, OctaPi's creators decided to develop their own. After three iterations, the software to manage the cluster is now based on Node.js, Bootstrap and Angular. So what is it all for? The press release says that: "The initial aim for the cluster was as a teaching tool for GCHQ's software engineering community....The ultimate aim is to use the OctaPi concept in schools to help teach efficient and effective programming."
Now I know that I'm generating good ideas.
Easier to do this with VM software and a big PC.
What, exactly, is retarded about it?
Linux, you magnificent bastard, I read the fucking manual!
Cluster? maybe. Super? hardly.
Can you really call something with the performance of a high-end desktop PC (or maybe a dual-processor workstation) a "super computer cluster"?
Slightly related: I created a cluster of raspberry pi's to do a distributed chess-game PuppetMaster. It participated in a CSVN (Dutch computer chess organisation) tournament and even won a couple of games! These little things can be pretty powerful.
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Since when does a collection of low powered machines ever deserve the term "Supercomputer"?
Even the TFA doesn't call it a Supercomputer.
All I can assume is a click-bait headline
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The reinvented a wheel (a cluster) that was useless (an "educational" cluster) and did it using low end, shitty parts (Raspberry Pis), then reinvented the software side of it, three fucking times, until they settled on a Frankenstein amalgam of "Node.js, Bootstrap and Angular".
Heh, back in the first dotcom boom I was working for some company that was making supercomputing clusters that were recursively scaleable. Back then you could get all the dumb, fast 8-port switches you wanted for cheap, but if you tried scaling it up with a big flat Cisco backplane for more than a few dozen nodes, you'd easily start paying more for switches than for computers. Plus if any of that infrastructure broke, you'd be out of a huge part of your cluster.
Shocked and amazed? anyone?
The only positive is that it's a 64-node cluster cheaply. The Pi's USB and ethernet implementations are absolute shit, requiring constant handling from the CPU to function. There've always been problems with dropped network and USB packets when the CPU is under heavy load. A Hardkernel ODroid-C1 uses the ARMv7 architecture instead of v6 (and has a quad-core CPU, to boot), has better ethernet, better USB, faster storage options, and costs the same as the Raspberry Pi. It beats out the RPi 2 in every way.
So, there's a better computer for the same price, which wouldn't have the unusually-strong requirement to avoid inter-node communication. The Pi's fine as a beginner's learning tool, but it's a bad model for scaling up to PC-type hardware that a "real" cluster would probably be built out of.
It is pitch black. You are likely to be eaten by a grue.
Hello,
This actually isn't a bad idea... as a training tool. It exposes GHCQ's interns (or other programmers and IT pros) who are not used to programming or managing clusters with the underlying concepts, so they can then go and apply those to whatever real projects they have.
Not everyone gets exposure to distributed computing concepts as part of their education, and having a small, simple system like this is a good and inexpensive means of introducing them to new hires. The homebrew cluster management software is another example of this.
Regards,
Aryeh Goretsky
Dexter is a good dog.
I manage a large compute cluster for my job. I also have a Pi and love it for what it is. Building a Pi cluster could give people an opportunity to try parallel programming, and learn the sysadmin side like getting a scheduler working or using Salt or similar management tool to manage a cluster.
However, I imagine a single Intel i5-4960 would smoke a 64-node Pi cluster. It's a worthwhile experiment, but probably not the best thing for most real-world use.
They said it's for educational purposes. The point isn't performance -- you're not getting that from RasPis. The point is either to train people on supercomputer programming or to test supercomputer programs on smaller data sets without using time on a real, expensive supercomputer.
I could see building a smaller scale one of these myself as a way to learn MPI.
RPI is quite inefficient.
2.4watts
0.041gflop
= 0.017 gflop/watt
i7-4790k
123.4 watts
117.35 gflop
= 0.951 gflop/watt
0.951/0.017 = ~56x faster. You'd need to spend $35 * 56 = $1960 on RPI's to get the performance of a single i7.
The C1 is pretty impressive but the Raspberry Pi Model 2 also has quad core ARM V7 and 1GB of RAM now. I might pick up a C1 to play with though, it has some neat stuff. It's the first $35 board I've seen that actually seems as good or better than the Rpi. I'd say the community around the pi might make it a better choice still. I picked up a couple of the Pi A+ boards and camera modules and for $45 dollars for the combo it's hard to beat for surveillance cameras. The A+ uses next to nothing in the way of power as well. I've been blown away by it and it fits in a damn Altoids tin. :)
Yet still higher than yours.
The article doesn't have any details about the extra hardware that's connected to the RPi boards.
From the low-res picture, you can see that in each 8-RPi unit, all Pis have a "PiGlow" connected and 4 of the 8 Pis have an extra network card (or another device with a RJ54 cable) plugged in the GPIO slot (with a pass-trough for the PiGlow)
Anyone knows what device is that ?
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Dross and misleading article, states they couldn't disclose the source of how to build one, maybe because they stole it from a South Hampton University Professors original work and would rather you didnt build one putting there fail to shame on public record! See: http://www.southampton.ac.uk/~... Beowulf clusters are a dime a dozen and easy enough to do, GCHQ is certainly not the first person to think of it, nor is there HQ somewhere I would advocate my child should work. The USAF already did something similar with PS2's (Playstation's to build a giant cracking cluster and all it could break was Rainbow Tables!) and if you expect your children to have common sense then perhaps it's something that should be distilled into them at an early age, a bit like morals and why hacking into phone's and spying on people is morally wrong! On the other hand however, most hilarious to read about how there Allies and there SPY website got hacked with weak encryption by a load of very peeved off hackers with Freaky SSL though!
Faster? yes. Better for training? No.
Buy a single damn video card.
You can get GeForces these days with up to 2,048 CUDA cores and the memory bandwidth to actually use them. A Raspberry PI is a cute toy--I have one--but anyone wanting to do massively-parallel computation has plenty of faster and cheaper choices out there. There's also the FPGA route if your routines are simple enough and you have enough of an EE background.
That's likely why he thinks it's retarded... it doesn't solve any problems that aren't better solved by other solutions.
The reinvented a wheel (a cluster)
Actually they reinvented the wheel not just in the generic sense but also in the specific sense that someone else has already built a 64 node Raspberry Pi cluster...and instead of some custom designed case theirs used a home build lego case which was definitely cooler. Of course this should not be too surprising. It was made by GCHQ after all so they probably got the idea from reading this guy's email!
Buy a single damn video card. [...] That's likely why he thinks it's retarded... it doesn't solve any problems that aren't better solved by other solutions.
I'm not seeing how a single video card will help solve the problem of teaching how to build a cluster out of multiple networked computers. Nor would it look nearly as cool, which is directly relevant to the purpose of (to quote TFA) "getting children interested in science and engineering". It sounds like what GCHQ came up with succeeds much better at achieving the goals in question.
"Convictions are more dangerous enemies of truth than lies."
but beowolf would approve!!!
The PI uses 4 watts, so a cluster of 64 PIs will use around 256 Watt. A NVidia GTX960 will provide 2,308 GFLOPS at 120 Watt or around 20 GFlops per watt. GTX980 is even better with 28 GFLOPS per Watt. Adapteva Epiphany-IV is supposed to do 100 Gflops at 2 Watt.
Tegra X-1 can do 512 GFlops at likely something between 5-10 Watts.
But even if you would build a Tegra X-1 cluster, for many applications it would still be less power efficient than a smaller number of more powerful machines with a good interconnect:
Even most parallel applications need some communication and exchange of results between the different threads. This will be very slow on the rasberry cluster.
But a rasberry pi cluster should be a good educational tool to teach cluster programming. Processing speed is slow, communication is also slow but the ratio between communication bandwidth and processing speed is likely quite similar to real clusters. So the skills that you learn when mapping small problems to a rasberry pi clusters can also be applied when mapping big problems to real clusters. And at the same time building one of these clusters is around the same price as a single compute node in a real cluster. So you can easily give students access to such a cluster.
You could solve the small problems way more efficiently using a single GPU, but if you want to solve the big problems a single machine is not going to be enough and you will have to deal with the limted communication bandwidth between the nodes.
Jan
That's kind of the point of educational projects.