[Beowulf] Southampton engineers a Raspberry Pi Supercomputer

[Lux, Jim (337C)]

Harkening back to earlier "make a beowulf of X".. one can hold a Furby in one's hand.

But anyway, this is kind of cool. It also shows some of the practical problems of scalability: cable management, for one.  Look at that picture of the 64 wall warts plugged into a bunch of plug strips. 

Here's an interesting question.. I agree with the thought that this kind of thing is useful for learning about using a cluster computer (as opposed to parallel programming), and in a way that isn't provided by emulation or multiple VMs or multiple cores running on one box.  The physical cable management is one aspect.  The complexity of moving software onto all nodes.. A blithe statement of " rinse and repeat for each additional node" should fill most people with terror, but doesn't, until you've had to do it.  Just pulling a SD card out, shoving it in, running some windows utility, etc. is a non-trivial amount of work.

So, the question is...   what's the smallest number of nodes in a "demo/toy" cluster that gives you the "big iron" feeling.  I'm going to guess that 4 is too few.   64 is clearly enough..   Most cheap non-rack mount, non-surplus ethernet hub/switches have 5-8 ports.  Maybe you need to have more than 8 nodes to really get into the "how do I interconnect N things when my interconnection device has only M ports", although you could trivially contrive such a thing (use only 4 ports on a 8 port switch)

I've done 4 nodes a bunch of times, and that seems a bit too trivial.  Heck, there's a lot of people who have 4 computers in their office, forming a defacto heterogenous cluster.


There's also that "as soon as we were able to source sufficient..." statement... 

And I *still* think that a cluster of arduinos would be fun, albeit slow.  Is there a (limited) MPI implementation?  There's some interesting I/O devices for arduino that might be intriguing in this context.. the 8x8 multicolor LED displays for instance.

Jim Lux


-----Original Message-----
From: beowulf-bounces at beowulf.org [mailto:beowulf-bounces at beowulf.org] On Behalf Of Eugen Leitl
Sent: Wednesday, September 12, 2012 6:55 AM
To: Beowulf at beowulf.org
Subject: [Beowulf] Southampton engineers a Raspberry Pi Supercomputer


http://www.southampton.ac.uk/mediacentre/features/raspberry_pi_supercomputer.shtml

Southampton engineers a Raspberry Pi Supercomputer

Professor Cox comments: “As soon as we were able to source sufficient Raspberry Pi computers.”

runs off a single 13 Amp mains socket 


“The team wants to see this low-cost system as a starting point to inspire and enable students to apply high-performance computing and data handling to tackle complex engineering and scientific challenges as part of our on-going outreach activities.”

James Cox says: “The Raspberry Pi is great fun and it is amazing that I can hold it in my hand and write computer programs or play games on it.”