John L. Gustafson leads the HPC workload characterization effort at Sun Labs. He joined Sun in 1999 after many years developing novel computer measurement approaches at Sandia and Ames Laboratory. Dr. Gustafson has won three R&D 100awards and has several patents, all in the area of computer system performance. His 1987 work with colleagues Gary Montry and Robert Benner at Sandia showed that the assumptions of "Amdahl’s law" might not be appropriate for many HPC workloads, and introduced the paradigm referred to as "Gustafson’s law" that removes unnecessarily pessimistic predictions about massively parallel computing performance.