Computer architecture is a truly fascinating field in tha improvements in the basic echnology and innovations how to make best use of he underlying tech- nology has yielded a performance growth exceeding a million times over the past 50 years. What is even more amazing is the fact that he pressure on maintain- ing his rate of performance growth shows no decline. In fact, as performance thresholds are passed, application designers face new opportunities tha give new challenging problems to work on for computer architects.