HPC ARCHITECTURE REQUIREMENTS FOR EARTH AND SPACE SCIENCE APPLICATIONS

Scalable high performance computer architecture brings substantial pro cessing, memory, and communications resources to large scientific and engineering applications while leveraging industrial investment and ra pid growth in VLSI microprocessor technology. These processor architec tures, while approaching supercomputer performance, were developed to support the workstation market and incorporate policies consistent wit h the needs of that user community. Large parallel computers differ fr om workstations in that they exhibit high diameter and experience extr emes in memory access latency. These architectures employ sophisticate d cache structures to minimize average latency and achieve high appare nt memory bandwidth. Unfortunately, many large scientific codes do not exhibit memory access patterns with the necessary locality of referen ce on which effective use of cache mechanisms relies. This presentatio n examines the memory access patterns of applications from the Earth a nd space sciences community and considers their implications for cache based architecture.