On the performance of concurrent transfers in collective algorithms
Juan‐Antonio Rico‐Gallego, Juan Carlos Díaz Martín · 2013
Inter- and intra-machine MPI collective operations in current multicore clusters are essentially different, and therefore their performance modelling ask for different approaches. Inside a multicore each individual message transmission in a collective operation flow in parallel with others, but sharing the bandwidth of the main memory channel. Current models ignore this issue, making errors like giving the same cost estimation to quite different collective algorithms. We outline a new cost model focused on shared channels.