[Beowulf] Re: the comparison between OpenMP and MPI

[Rich Altmaier]

Hi, I strongly suggest you slightly violate your desire for freeware tools.
After all, getting good data and efficient use of your time can be
more valuable than finding the cheapest tools.
Our hands-on experience with many codes suggests
the Intel tool set can handle far more complex codes than
open source compilers.
When you need 100k lines of Fortran to compile correctly,
you won't find an open source answer, in my opinion.

http://www.intel.com/cd/software/products/asmo-na/eng/index.htm
Take a look at the compiler, Vtune, libraries, thread analysis tools,
and cluster tools.  Intel's delivery of software developer tools
here is very strong.  The compiler supports OpenMP.
For the MPI library, probably you should go with MVAPICH,
http://mvapich.cse.ohio-state.edu/
Presently I see mvapich as strong for bandwidth and latency, for
a large number of nodes.

In your comparison, try this: once you have an optimal MPI code,
convert it back to OpenMP and see how the balance between compute
and communication can act in your favor.

Just FYI,
Rich Altmaier, SGI