Evaluating CP2K on Exascale Hardware: Intel Xeon Phi

CP2K, a popular open-source European atomistic simulation package has been ported to the Intel Xeon Phi architecture, requiring no code modifications except minor bug fixes. Benchmarking of a small molecular dynamics simulation has been carried out using CP2K’s existing MPI, OpenMP and mixed-mode MPI/OpenMP implementations to achieve full utilisation of the Xeon Phi’s 240 virtual cores. Running on the Xeon Phi in native mode, CP2K is approximately 4x slower than utilising all 16 cores of a Xeon E5-2670 Sandy Bridge dualsocket node. Careful placement of processes and threads on the virtual cores of the Xeon Phi was found to be crucial in achieving good performance.

Analysis of the benchmark results has led to the identification of a number of bottlenecks which must be resolved to achieve competitive performance on the Xeon Phi, which will be carried out as a follow on to the work reported here.