There seems to be a growing interest in the Raspberry Pi Foundation’s bare-bones, low cost (ca. $35) single-board Linux computer, the Raspberry Pi, designed originally for educational applications. I noted earlier this month that the University of Cambridge Computer Laboratory was offering a free online course in operating system design, based on the Raspberry Pi. This past week, Wired has published an article about another interesting development from the UK.
Though small, the little computer has respectable capabilities. The first offering, the Model B board, mounts a 700 Mhz ARM CPU, a GPU, 256 MB of memory, audio, HDMI, and RCA video outputs. an Ethernet connection, and two USB ports; there is also a slot for an SD memory card. Simon Cox, a professor of computational methods at the University of Southampton, originally bought a Raspberry Pi to use with his six-year-old son. He then got the idea of using a number of the devices to build a supercomputer — with a case made out of Legos!
The resulting computer (the Wired article also has a set of photos) cost about £ 2,500 (a little over $ 4,000), not including networking equipment. It has 64 Raspberry Pi computers, each with a 16 GB SD memory card, giving a total of 1 TB in addition to the on-board memory in each device. The nodes communicate with each other using the Message Passing Interface standard, developed by the Argonne National Laboratory. Professor Cox has a Web page with links to a number of resources, including instructions [PDF] for building your very own supercomputer. You can even install a FORTRAN compiler.
The setup developed by Prof. Cox and associates is not ideal in some ways; for example, it requires 64 power supplies, one for each Raspberry Pi. But it seems like an excellent tool for teaching students about massively parallel computing.