Performance analysis of a cardiac simulation code using IPM

This paper details our experiences in performing a detailed performance analysis on a large-scale parallel cardiac simulation by the Chaste software on an Nehalem and Infiniband-based cluster. Our methodology achieves good accuracy for relatively modest amounts of cluster time. The use of sections in the Chaste internal profiler, coupled with the IPM tool, enabled some detailed insights into the performance and scalability of the application. For large core counts, our analysis showed that performance was no longer dominated by the linear systems solver. The computationally-intensive components scaled well up to 2048 cores, and poorly scaling and highly imbalanced components associated with program output and miscellaneous functions were limiting scalability.