I’m compiling and running a Fortran 90 program using OpenAcc. I was able to run the code with openacc directives in my local PC using PGI compiler. But now I’m trying to run the same program in a cluster (on a single node which has 4 GPUs - Volta 100) with GCC (compiler version 8.2) and I’m starting to face issues. I run the program 1st using the following command line:-
gfortran -fopenacc --gres=gpu:volta:1 test.f90
and it gives the following error “gfortran: error: unrecognized command line option ‘–gres=gpu:volta:1’”
then I try running it using following command lines; the code runs but the former takes 167 sec and the latter takes 137 sec, compared to the same code I ran in my local PC which took 3.67 sec (GTX 1050).
gfortran -fopenacc test.f90
gfortran -fopenacc -lcuda test.f90
I’m not if my program is utilizing the GPUs or the problem is related to the efficiency of the code with different compilers (as reported here https://www.openacc.org/sites/default/files/inline-images/UserGroupMeeting/OpenACC_Randy_allen_Usergroup.pdf). Any feedback would be helpful. Thank you in advance!