Heterogeneous Gpu-Cpu Computing For Electro-Cardiac Simulations.

Detailed organ-scale simulations of calcium handling and electrical signal transmission in the human heart require stochastic simulation of a large number of ion channels in each cell, which consumes immense processing power for the simulation of a single heartbeat, thereby creating the need for large scale parallel implementations. We present codes for solving such cardiac models on structured and unstructured meshes, and discuss the challenges involved in :modernizing these codes to run on heterogeneous supercomputers. We focus on the interaction between OpenMP, MPI, and CUDA in such computations, as well as optimizations to communication and vector processing, and illustrate practical experiences with these applications on different supercomputers.