Data motion and high performance computing

Efficient data motion has been of critical importance in high performance computing almost since the first electronic computers were built. Providing sufficient memory bandwidth to balance the capacity of processors led to memory hierarchies, banked and interleaved memories. With the rapid evolution of MOS technologies, microprocessor and memory designs, it is realistic to build systems with thousands of processors and a sustained performance of a trillion operations per second or more. Such systems require tens of thousands of memory banks, even when locality of reference is exploited. Using conventional technologies, interconnecting several thousand processors with tens of thousands of memory banks can feasibly only be made by some form of sparse interconnection network. Efficient use of locality of reference and network bandwidth is critical