IntelĀ® MPI Benchmarks User Guide and Methodology Description
Before starting the actual benchmark measurement for IMB-MPI1, IMB-EXT, IMB-NBC, and IMB-RMA, the selected benchmark is executed N_WARMUP times with a sizeof(assign_type) message length. The N_WARMUP value is defined in IMB_settings.h, see Parameters Controlling IntelĀ® MPI Benchmarks for details. The warm-up phase eliminates the initialization overhead from the benchmark measurement.