To run one of the DGEMM timing codes, you must first compile one of the codes, modify the LD_LIBRARY_PATH to ensure that the proper libraries are linked, set the number of threads to use, and then run the code. For example: After copying the files in /tmp/M697/BENCH_ACML_DGEMM to one of your directories, one would, e.g. ./compile_gfortran_acml source ./SET_LD_LIBRARY_PATH export OMP_NUM_THREADS=2 ./a.out