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Building a supercomputer from 64 Raspberry Pis and Lego
- Sukotto 14y agomore info (and build plans) here: http://www.southampton.ac.uk/~sjc/raspberrypi/ http://www.southampton.ac.uk/~sjc/raspberrypi/
- K2h 14y agoI was trying to find a real comparison of MIPS of this thing compared to an I7 and landed on this page for performance data for the RPi. The most interesting thing to me is power consumption data at the bottom - that shows idle with network is around 370mA, which should mean (ignore power supply efficiencies) that 64 of these things should use about 120W at idle. http://www.elinux.org/RPi_Performance http://www.elinux.org/RPi_Performance
- regularfry 14y agoHow do you get 120W? I get 24W.
- synx508 14y ago0.37amps X 5volts X 64
- regularfry 14y agoOh, I'm an idiot. Misread it as 370mW.
- EwanToo 14y agoMy beaglebone consumes about 1.7W so that sounds about right. One interesting thing is that the USB port being activated (even idle) can blow any power consumption by the CPU itself out of the water.
- jrabone 14y agoIf those are switch-mode power supplies most of the that current will be drawn out of phase (ie. imaginary power); not important to the domestic customer, as the meter probably won't read it, but important to the supplier, who will come and make you fit power correction equipment to your supply :-)
- smortaz 14y agowhat a pleasant surprise to see our little OSS project mentioned/used... surprised as this is a Windows/VS Python IDE & they're running Linux on the nodes - http://pytools.codeplex.com http://pytools.codeplex.com
- fpp 14y agoA technical description and how they got it running together with more pictures: http://www.southampton.ac.uk/~sjc/raspberrypi/pi_supercomputer_southampton.htm http://www.southampton.ac.uk/~sjc/raspberrypi/pi_supercomput... As you can see from the pictures each of the devices uses its own power supply, so there should be quite some possibility to improve overall power consumption. Anybody with more experience of using MPI ?
- bravura 14y agoI programmed MPI about 15 years ago, during a summer at the MIT AI Lab. I implemented neural network feature creation for a backgammon agent ("Automated feature selection to maximize learning in artificial intelligence"). Nowadays, I mainly do parallel machine learning on machines with higher network latency. I haven't used MPI since.
- apawloski 14y agoWhat do you use now instead of MPI?
- pm90 14y agoHe talked about higher latency so I'm guessing just sockets
- bravura 14y agoIncorrect. With the sort of work I do nowadays (large-scale ML and NLP), I generally need very little synchronization, i.e. my tasks are usually embarrassingly parallel. I typically save final results in a centralized store (DB or NFS) and look at it there. I also use Hadoop where appropriate.
- apawloski 14y agoIt is almost always the case that programs written for clusters -- including those which use MPI -- are communication bound. Right now the limiting factor is not these little processors, but rather the interconnect speed. If I remember correctly, Raspberry Pi has 10/100 megabit ethernet. [Edit: just checked, this is the case] So while this looks like a lot of fun, it's not very useful for anything meaningful yet. Of course it's not fair to compare this to an infiniband cluster (that's not the point of this exercise), but I'd really be interested to see a cluster built on $0.50 ARM chips with at least a gigabit ethernet interconnect. A couple of years from now -- given the low entry cost and lower infrastructure costs (cooling/power consumption/etc) -- that could be a game changer.
- jevinskie 14y agoI wonder how this compares to a Microwulf cluster [0] in terms of cost / gigaflop. I'm guessing it isn't very efficient. [0]: http://www.calvin.edu/~adams/research/microwulf/ http://www.calvin.edu/~adams/research/microwulf/
- wickberg 14y agoRasPi is ~ 175 MFLOPS per unit (CPU only, discounting the GPU). So, this cluster works out to 11 GFLOPS, with 16GB of RAM for > $2500 USD. For comparison, you could buy a motherboard, 32 GB of RAM, and an Intel i5 processor for $500 that will do over 20 GFLOPS. So, it doesn't really stack up well from a price/performance standpoint. The value of these systems is more teaching students how to work with parallel code.
- deleted 14y ago[deleted]
- thereallurch 14y agoNo, 256 MB of RAM on each rasp. It's 16GB of storage on each rasp.
- markdl 14y ago64 rasps x 256mb = 16 gb total ram
- aortega 14y ago> The value of these systems is more teaching students how to work with parallel code. There are no practical applications to this, it's just to show that it can be done. You can spawn 64 processes in a Core I7 and it would be about the same, just faster. Or 64 VMs. Maybe the real value of these systems is to teach students to design and calculate before building it.
- wickberg 14y ago
- msprague 14y agoPictures http://www.southampton.ac.uk/~sjc/raspberrypi/pi_pictures.htm http://www.southampton.ac.uk/~sjc/raspberrypi/pi_pictures.ht...
- deleted 14y ago[deleted]
- deleted 14y ago[deleted]
- Tichy 14y agoWould 64 Raspberry Pis actually be faster than a single current Intel CPU? Just asking... it probably was a fun project anyway...
- lallysingh 14y agoNo, not even close. This is more of a fun decoration you have in your home for visitors, as a conversation piece.
- philip1209 14y agoI submitted the same story from a different source four hours before . . . http://news.ycombinator.com/item?id=4510931 http://news.ycombinator.com/item?id=4510931
- sciurus 14y agoBut you should have submitted this source instead. From http://ycombinator.com/newsguidelines.html http://ycombinator.com/newsguidelines.html "Please submit the original source. If a blog post reports on something they found on another site, submit the latter. "
- krohrbaugh 14y agoThis is pretty cool. On the other hand, stop sucking up all the supply for Raspberry Pis! My order keeps getting delayed and it's making me sad.
- montecarl 14y agoI ran some numerical simulations on my Raspberry Pi and on my laptop. With the LCD on, my laptop used 20.4 watt seconds to do the calculation and the RPi used 17.1 watt seconds. The RPi drew 3 watts and my laptop drew about 60 watts. I think, even with my screen on, that my laptop would be more efficient if I had used 2 cores instead of 1 in the calculation (or if I had just turned off the LCD). My conclusion, the RPi doesn't even win in FLOPS/Watt let alone $/FLOPS.
- anthonyb 14y agoDoes it have to? It sounds like they're using this as a learning platform rather than a serious $/FLOP/Watt cluster. In that case you'd want to make it easy to get funding, and be optimising for initial cost. What would be the cost of 64 of your laptops?
- montecarl 14y agoIt certainly doesn't have to! I just wanted to share the results of an experiment I did with numerical computing on the RPi. Certainly laptops aren't the idea platform to compare against anyways. I'd compare to a 1u node that you would buy for compute cluster. One can by a 64 core 1u node with 64 GB of ram for about $7k. If one wants to play around with cluster computing you can emulate an entire cluster using one of those!
- fhars 14y agoOf course that may (or may not) change if the RPi foundation will be able to get the programming documentation for the DSP/GPU part of the processor a recent blog post hinted at.
- gaius 14y agoWell you are missing the point a bit: the RPi's mission is to be an accessible platform for teaching kids to code on. It's role as a toy for former-80s-8-bit-geeks is secondary.
- darklajid 14y agoThat might matter for a cluster, but that's (obviously) not the target market for a Pi. If you only have less than $100 to spend, a better $/FLOPS ratio of a MacBook (or anything else, really) doesn't matter. One is available, one is plainly not. For people that CAN spend enough this usually is just a (third? nth?) gadget to play with. Like in the article (because, it's really just a neat way of playing with gadgets and lego, not 'useful' in any sense that can be quantified).
- jff 14y agoNifty... but did you really write 64 SD cards, one after another? This is 1995-level clustering, you gotta PXE boot.
- noonespecial 14y agoCan RasPi's netboot? I honestly don't know. I still haven't gotten one yet. Still waiting since placing the order. The amazing thing about this project? Someone managed to get 64 RasPi's all in the same place!
- sitkack 14y agoThey cannot netboot. The bootloader is crap.
- jff 14y agoUgh. It's the same with the Efika MX hardware, otherwise nice systems, made incredibly painful by the lack of 1970s technology.
- ChuckMcM 14y agoWell to be explicit, the cannot netboot directly. I've built a u-boot that boots from the network via NFS on other arm based systems. You still need an MMC card to start it all off but once you get the network boot loader loaded and running you can do what ever you want. I started with some code for the Pandaboard that used that trick to boot from a USB attached drive.
- sitkack 14y agoI will have to look into this, http://kernelnomicon.org/?p=133 http://kernelnomicon.org/?p=133 u-boot on the raspberry pi.