CONSISTENT APPLICATION PERFORMANCE AT THE EXASCALE

We examine the future of application performance consist-ency on exascale parallel computing systems. By perform-ance consistency we mean the regularity of wall clock times to complete a fixed amount of application progress. Exascale systems will have dramatically increased com-plexity along with their capability. Contributors to inconsist-ency include architectural choices, software functions and subtle interactions, and inconsistency will lead to lost potential. The challenge is how to maintain consistency at the exascale. In order for exascale systems to exhibit the consistency that is required to make the applications and systems productive, a new understanding of the causes and solutions to inconsistency is required, along with new ways of measuring the impact that design, implementatio