[Beowulf] RE: programming multicore clusters

[Matt]

Joseph Mack writes:

 > I expect everyone here knows all this. How is everyone going 
 > to program the quadcore machines?

We used OpenMP on the node and MPI between the nodes. It's ugly and
horrendous to look at or comprehend. The only saving grace is that our
source code is serial plus custom directives and we have tools to
generate OpenMP or calls to a MPI based library or both. So we put all
the difficult stuff in the directives. We don't have any SMP nodes
anymore so it will take some time to resurrect that ability.

Using straight MPI is the lowest common denominator and simplest, but
doesn't use the machine very efficiently. I think it'll only get worse
with more cores.

I'd be interested in your experience and what you find out.

Matt