XSEDE OpenACC workshop enables Blue Waters Researchers to Accelerate Key Algorithms

Abstract

The Blue Waters system at the National Center for Supercomputing Applications (NCSA) is the largest GPU accelerated system in the NSF's portfolio with greater than (>) 4200 Nvidia K20x accelerators and greater than (>) 22500 compute nodes overall. Using the accelerator nodes effectively is paramount to the system's success as they represent approximately 1/7 of system peak performance. As an XSEDE level 2 service provider, the system is also available to education allocations proposed by XSEDE educators and trainers. The training staff working at Pittsburgh Supercomputing Center (PSC) along with their XSEDE and Nvidia partners have offered multiple OpenACC workshops since 2012. The most recent workshop was conducted on Blue Waters hosting the hands-on sessions and it was very successful. As a direct result of working with PSC on these workshop, NCSA researchers have been able to obtain significant speedups on real-world algorithms using OpenACC in the Cray environment. In this work we will look at two key kernel codes (3D FFT kernel, Laplace 2D MPI benchmark) and the path to obtaining the observed performance gains.