When compiled with the Cray Fortran compiler, the coarray version of ICAR scales to very high concurrencies - nearly 100 000 images on the Edison system at NERSC, and up to several 10 000s of images on Intel Xeon Phi on the Cori system at NERSC. However, the OpenCoarrays version, compiled with Cray MPI, scales poorly on Xeon Phi, even at relatively low concurrencies. We should investigate the cause of this poor scaling and determine how it can be fixed in OpenCoarrays.
When compiled with the Cray Fortran compiler, the coarray version of ICAR scales to very high concurrencies - nearly 100 000 images on the Edison system at NERSC, and up to several 10 000s of images on Intel Xeon Phi on the Cori system at NERSC. However, the OpenCoarrays version, compiled with Cray MPI, scales poorly on Xeon Phi, even at relatively low concurrencies. We should investigate the cause of this poor scaling and determine how it can be fixed in OpenCoarrays.