About the Author
John Levesque works in the Chief Technology Office at Cray Inc., where he is responsible for application performance on Cray’s HPC systems. He is also director of Cray’s Supercomputing Center of Excellence at the Oak Ridge National Laboratory (ORNL). ORNL was the first site to install a Petaflop Cray XT5 system, Jaguar; as of June 2010, it is the fastest computer in the world according to the TOP500 list.
For the past 40 years, Mr. Levesque has optimized scientific application programs for successful HPC systems. He is an expert in application tuning and compiler analysis of scientific applications.
Gene Wagenbreth is a senior system programmer in the Information Sciences Institute at the University of Southern California, where he is applying GPGPU technology in sparse matrix solvers, image tomography, and real-time computational fluid dynamics. He also presents courses on the use and programming of GPUs.
Since the 1970s, Mr. Wagenbreth has worked with most of the highest performance computers, including Cray models, other vector processors, hypercubes, and clusters. He has worked with shared and distributed memory computers using MPI, OpenMP, pthreads, and other techniques. He has also applied parallel processing in numerous fields, including seismic analysis, reservoir simulation, weather forecasting, and battlefield simulations.