Automatic Parallelization - same execution time with different number of threads

[A__Hamid]

Hi all

I am doing some experiment on auto-parallelization tools on NAS benchmark, by using Intel icc V18 (FLAGS : -parallel -g -O2 ), even by changing the number of threads (export OMP_NUM_THREADS=4, 8 or 16) always I got the same execution time (it happened for all NAS benchmarks and not just for some of them) !!!

should I use any additional flag ???

Thanks

[Viet_H_Intel]

Do you see the different execution time if you compile with GCC for 4, 8, 16 threads?

Thanks,

Viet 

[McCalpinJohn]

You should look at the optimization reports to find out if the automatic parallelization was actually able to parallelize the important loops....