> On Jan 6, 2016, at 23:31, Christopher Samuel <[email protected]> wrote: > >> On 07/01/16 01:03, Novosielski, Ryan wrote: >> >> Since this is an audience that might know, and this is related (but >> off-topic, sorry): is there any truth to the suggestions on the Internet >> that using srun is /slower/ than mpirun/mpiexec? > > In our experience Open-MPI 1.6.x and earlier (PMI-1 support) is slower > with srun than with mpirun. This was tested with NAMD. > > Open-MPI 1.8.x and later with PMI-2 is about the same with srun as with > mpirun.
Thanks very much to both of you who have responded with an answer to this question. Both of you have said "about the same" if I'm not mistaken. So I guess they're still is a very slight performance penalty to using PMI2 instead of mpirun? Probably worth it anyway, but I'm just curious to know the real score. Not a lot of info about this other than the mailing list. Thanks again.
