Improving the scalability of CP2K on multi-core systems

Abstract

Six months of HECToR dCSE funding was given to implement mixed-mode OpenMP parallelism in CP2K, building on the results of an earlier successful dCSE project. Improved scalability of up to 8 times as many cores was demonstrated for a small benchmark, and a larger, inhomogeneous benchmark was shown to scale up to 9000+ cores. An increase in peak performance of up to 60% was also realised on HECToR Phase 2b. In addition, the performance of the code was studied on three generations of Cray systems - XT4, XT5 and XT6 - and under four different compilers.