NAMD Wiki: NamdOnInfiniBand
NAMD can utilize InfiniBand networks via the Charm++ ucx, verbs, or mpi network layers.
The ucx layer (new in NAMD 2.14) is expected to give the highest performance for both smp and non-smp builds, but is not portable between machines and must be compiled from source code (see NamdOnUCX).
NAMD binaries using the portable verbs layer are available for download starting with NAMD 2.11.
The portable ibverbs layer is discontinued after NAMD 2.13. Use the newer verbs layer instead.
The mpi layer has acceptable performance for non-smp builds but should be avoided for smp builds.