Multi-threading Test Programs

Hey guys,

I am trying to test two chips on my computer. Can someone suggest some algorithms I can run that can be parallelized easily using OpenMP. Preferably no recursion. Examples of some are fft, matrix multiplication and etc.

Furthermore, I found this non-recursive version of quicksort here.
http://www.seeingwithc.org/topic2html.html
I have been trying to parallelize it using OpenMP but so far I have only achieved speedup results with only 2 threads. I want to be able to test runtimes for 4 - 8 threads and observe speedups. Can anyone suggest any changes to the non-recursive quicksort algorithm found on that website that can help speedup the process for 4 - 8 threads?

Im new to OpenMP.

Your help is greatly appreciated.