jargon.artrocity.com
New Hacker's Dictionary the Jargon File v 4.4.6
Used to describe a person who is technically brilliant but can't seem to communicate with human beings effectively. Technically it describes a machine that has lots of processing power but is bottlenecked on input-output (in 1991, the IBM Rios, a.k.a. RS/6000, was a notorious example).