Implementation of NEMO global 1km ocean-only demonstrator and performance analysis (D2.10)

Popularity of one kilometre scale global geophysical models is continuously growing in Europe. In this study, we increase the resolution of the NEMO ocean model, to better identify technical limitations of the present implementation and deduce, from the performance measured on one of our top supercomputers, the hardware characteristics needed to routinely use a global ocean one kilometre configuration. 24,000 Intel Broadwell cores of the Météo-France supercomputer are required to measure the performance of a simplified version of NEMO global kilometre scale. From them, assuming a perfect scaling up to 9,000,000 (nine million) computing cores, we infer that we could target a maximum speed of approximately 2 SYPD with the ORCA-Km global model.