This needs to be investigated further. 2.1.0.9 IBM's MPL ver. 2.1.0.9 IBM's MPL ver. In general, MPL still outperfoms MPI but not by very much. All measurements exhibited the same Poisson distribution explained earlier.
Experimental results are in close agreement with the simple communication model derived.
Recommendations and Conclusion. For best performance, use MPL with TB2 and TB0 adapters. Conversion from MPL to MPI for portability is relatively simple. There is an improvement in going from TB2 to SPS adaptes but here the percentage performance improvement in bandwidth is smaller and achievable only for much larger message sizes. A simple model was created and used to estimate timing expressions for the basic communication routines.