[gmx-developers] MPI enabled FFTW and GROMACS

[Joshua J. Hursey]

I have a architecture related question for anyone able to answer it.

According to some of the comments that I have seen in the source, and
related documentation, a MPI enabled GROMACS requires a MPI enabled FFTW
to run (and I believe the converse to be rue as well: an MPI disabled
GROMACS requires a MPI disabled FFTW installation).

Does GROMACS use MPI calls that call FFTW MPI calls or:
Does GROMACS use just FFTW MPI calls?

I have been working my way through the source files trying to answer this
one, and thought that maybe someone could enlighten me. From what I have
seen the former seems to be the case where GROMACS is parallelizing then
in those parallelizations we have FFTW parallelizing. How wrong am I?

Cheers,
Josh Hursey