Performance Characteristics of HYDRA – A Multi-physics Simulation Code from LLNL [chapter]

Steven H. Langer, Ian Karlin, Michael M. Marinak
2015 Lecture Notes in Computer Science  
HYDRA is used to simulate a variety of experiments carried out at the National Ignition Facility (NIF) [4] and other high energy density physics facilities. HYDRA has packages to simulate radiation transfer, atomic physics, hydrodynamics, laser propagation, and a number of other physics effects. HYDRA has over one million lines of code and includes both MPI and thread-level (OpenMP and pthreads) parallelism. This paper measures the performance characteristics of HYDRA using hardware counters on
more » ... an IBM BlueGene/Q system. We report key ratios such as bytes/instruction and memory bandwidth for several different physics packages. The total number of bytes read and written per time step is also reported. We show that none of the packages which use significant time are memory bandwidth limited on a Blue Gene/Q. HYDRA currently issues very few SIMD instructions. The pressure on memory bandwidth will increase if high levels of SIMD instructions can be achieved.
doi:10.1007/978-3-319-17353-5_15 fatcat:266nc62pejf55hob77ceaf7ypu