Optimizing Science Applications for the Cori, Knights Landing, System at NERSC

In this chapter, we present the optimization strategy developed at NERSC for moving user applications from traditional x86 CPU based HPC systems to the many-core Xeon-Phi powered Cori system. We target the Xeon-Phi many-cores, large vector units and high-bandwidth memory. The developed strategy is general, intended to be applicable to NERSC's 6,000 users. We present three application case studies from different science areas to illustrate the Cori optimization process.