The list is the best-known ranking of supercomputer performance. Only a handful of companies in the world produce a computer this fast, and the least expensive costs well over a million dollars. Avalon is built out of 68 high- end personal computers that use the Digital Equipment Corporation Alpha microprocessor, connected by 3Com network switches similar to those found in a university department or small business. Each processor in the Los Alamos supercomputer is an ordinary PC, using the same type of memory and disk drives found in a computer on an office desktop. But hardware is only half of the equation.
Software is the hardest part of getting many processors to work together on the same problem.
The Los Alamos team used an open source Linux operating system and other software available on the Internet. Linux can be obtained at no cost through the Internet, but that is minor compared to its other advantages. In my experience, the reliability and performance of Linux has no peer. We have stressed Linux well beyond where one would expect it to fail, and it has performed admirably. If we can't fix it ourselves, we can tap the huge pool of Linux expertise on the Internet.