Hybrid parallelization of molecular dynamics simulations to reduce load imbalance

The most widely used technique to allow for parallel simulations in molecular dynamics is spatial domain decomposition, where the physical geometry divided into boxes, one per processor. This can inherently produce computational load imbalance when either distribution of particles or cost particle not uniform. paper shows benefits using a hybrid MPI+OpenMP model deal with this imbalance. We consider LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator), prototypical simulator that provides its own balancing mechanism and an OpenMP implementation many modules, allowing setup. In work, we extend current optimize it evaluate three different setups: MPI-only, MPI balance mechanism, setup our improved version. comparison made five standard benchmarks included plus two additional test cases. Results show approach problems better more effectively (50% improvement versus MPI-only highly imbalanced case) than (only 43% improvement) improve issues other