The Assessment of Bandwidth Requirements for Meteorological Code VARSHA on a Parallel Computing System

Complex scientific problems like weather forecasting, computational fluid and combustion dynamics, computational drug design etc. essentially require large scale computational resources in order to obtain solution to the equations governing them. These solutions are obtained by developing large legacy codes and then executing them using parallel processing systems as they require large scale computations. The parallel processing computers generally demand huge bandwidth as they consist of large number of networked processing elements. One such legacy code VARSHA is a meteorological code used for weather forecasting developed at Flosolver, CSIR-NAL under the joint project from NMITLI (New Millennium Indian Technological Leadership Initiative) and MoES (Ministry of Earth Science). The VARSHA is being run on a large scale computing platform, the Flosolver Mk8, the latest of the Flosolver series of parallel computers. This paper discusses the bandwidth utilisation of VARSHA code on Ethernet based interconnect, in its existing and modified forms in order to access the bandwidth requirements of such legacy codes on parallel computing systems.