Wee Archlet: our homemade Raspberry Pi cluster

When we started our outreach activities at EPCC, we wanted to allow the general public to use an application running on a real supercomputer. We developed an appropriate molecular dynamics-based application that actually ran on ARCHER, the UK national supercomputing service, which is hosted by EPCC. 

However, although it ran a lot faster than on a laptop, the activity didn’t convey the experience of working with a supercomputer or give the user new information. In short, no wow factor. 

The solution was to create a representative self-contained supercomputer that we could take to events and which would show the principle behind the parallelism that underpins supercomputing. We were able to do this when we  obtained funding through the Engineering and Physical Sciences Research Council, and so Wee ARCHIE was born. 

Based on 18 networked Raspberry Pi’s, Wee Archie has an attractive set of LED lights that convey some of the excitement of supercomputers. After all, Thinking Machines had done it with their CM-5 that appeared in the film “Jurassic Park”, so why not us? Moreover, we could run our previous demonstrators on this system, possibly not as fast as on the actual supercomputers, but enough to demonstrate the underlying principles that larger systems employ. 

But you don’t need the fancy packaging of Wee ARCHIE to develop a viable Raspberry Pi cluster. Normal Raspberry Pis with simple packaging such as brick casing (for example LEGO), can be used instead - we call ours Wee Archlet. 

Learning how to connect all of the elements together to form a clustered network is interesting, and the resulting system can be used to explore how supercomputers work. 

To support this, we have produced a set of instructions for how to build a Raspberry Pi-based cluster.

See: http://bit.ly/2qLEILx

You can contribute to these instructions yourself via GitHub or note any issues here:

http://bit.ly/2rsQATm

I would love to hear the experiences of anybody who builds their own Raspberry Pi cluster using our instructions!