Interconnection Networks

Foreword to the First Printing

William J. Dally,     Massachusetts Institute of Technology

The performance of most digital systems today is limited by their communication or interconnection, not by their logic or memory. In a high-end system today, most of the power is used to drive wires, and most of the clock cycle is spent on wire delay, not gate delay. As technology improves, memories and processors become smaller, faster, and less expensive. The speed of light, however, remains unchanged. The pin density and wiring density that govern interconnections between system components are scaling at a slower rate than the components themselves. Also, the frequency of communication between components is lagging far beyond the clock rates of modern ...