[Omp] slow performance

[Nils Smeds]

mcwang88 at hotmail.com said:
> But to my big suprise, I see that the result is quite different from what I
> can  imagine. The more threads I have, the more slow the calculation is.

You need to tell us more about the platform you are running on. How many processors
are available? How many processors are in use? Is there any other processes running
that may interfere with your application? What kind of processors? Operating system?

You enter and exit a parallel region 16200*50 times. The 39 second overhead then
divides into 39s/(16200*50) = 48µs per fork-join which sounds a little high on a 
modern system, but it is not outrageously high.

/Nils