Original post is here: eklausmeier.goip.de
Georg Hager's Blog posted an illustrative article on icc versus g++ performance w.r.t. OpenMP. Dr. Georg Hager is one of the authors of Introduction to High Performance Computing for Scientists and Engineers.
Measurement of
double precision, dimension(N) :: a,b,c,d
! initialization etc. omitted
s = walltime()
!$omp parallel private(R,i)
do R=1,NITER
!$omp do
do i=1,N
a(i) = b(i) + c(i) * d(i)
enddo
!$omp end do
enddo
!$omp end parallel
e=walltime()
MFlops = R*N/(e-s)/1.e6
gives