A Conversation with Steve Furber
The designer of the ARM chip shares lessons on energy-efficient computing. If you were looking for lessons on energy-efficient computing, one person you would want to speak with would be Steve Furber, principal designer of the highly successful ARM (Acorn RISC Machine) processor. Currently running in billions of cellphones around the world, the ARM is a prime example of a chip that is simple, low power, and low cost. Furber led development of the ARM in the 1980s while at Acorn, the British PC
... ompany also known for the BBC Microcomputer, which Furber played a major role in developing. In our interview this month he shares some of the lessons on energy-efficient computing he has learned through working on these and subsequent projects. He also fills us in on the innovative work he is doing at Manchester University, where he is a professor of computer engineering in the School of Computer Science. Furber's SpiNNaker (Spiking Neural Network Architecture; http://intranet. cs.man.ac.uk/apt/projects/SpiNNaker) project is a massively parallel system designed to simulate the workings of part of the human brain. Composed of a million ARM processors, SpiNNaker could help unravel some of the mysteries of the brain and eventually could provide valuable lessons on energyefficient, fault-tolerant computation. Interviewing Furber is Queue editorial board member David Brown, who met Furber at Cambridge University, where they both received Ph.Ds. Brown, an engineer in Sun's Solaris Engineering Group, has also thought a lot about energy-efficient computing. He works on the Solaris operating system's core power-management facilities, with a particular focus on Sun's x64 hardware platforms. Brown's resume prior to coming to Sun includes stints at Silicon Graphics, which he cofounded, and DEC, where he helped build the team that developed the graphics architecture for DEC's MIPS workstations. DAVID BROWN Can you tell us a little about your background and the early history of Acorn leading up to the BBC Microcomputer? STEVE FURBER I was born and brought up in Manchester, U.K., and went to university in Cambridge. My first degree was in maths, and then I did a postgraduate year in maths before going into the engineering department to do a Ph.D in aerodynamics. In the course of my Ph.D work and the research fellowship in aerodynamics that followed, I got increasingly involved in using computers to get results from my aerodynamics experiments. I got interested in how computers work, and I joined the Cambridge University Processor Group when it formed around 1977-78. This was a student society for those of us who liked building computers for fun. I built a machine using a Signetics 2650 microprocessor, an 8-bit micro that we had to order from California, which in those days was a bit exciting. I bought this and some other parts and wired a small machine together. At that time, Hermann Hauser and Chris Curry were looking to form a company, which became Acorn Computers. They naturally went to the Cambridge University Processor Group to look for people with the technical knowledge to do some of the work, and I slowly got drawn into the embryonic Acorn.