Scalability of data transport

Peak floating point rate is a very limited way to characterize high performance computer systems. A better method is to use the bandwidth and latency of data transport for the major components of a system. Bandwidth scales well with increasing system size, but latency does not. The demands placed by a program on data transport determine how well an architecture will execute it. The article discusses two program metrics which describe latency characteristics of programs and shows how they can help optimize program structure.<<ETX>>