[Beowulf] Shared memory
john.hearns at streamline-computing.com
Thu Jun 23 00:44:32 PDT 2005
On Wed, 2005-06-22 at 08:46 +0100, Mark Westwood wrote:
> My thinking is that mixed-mode programming, in which a code uses MPI for
> inter-node communication and shared-memory programming (eg OpenMP) for
> intra-node communication, is not worth the effort when you only have 2
> CPUs in each node. In fact, my thinking is that it's not even worth the
> time experimenting to gather evidence. I guess that makes me prejudiced
> against mixed-mode programming on a typical COTS cluster. Now, if you
> were to offer me, say, 8 or 16 CPUs per node, I might think again. Or
> indeed if I am shot down in flames by contributors to this list who have
> done the experiments ...
Mark, that is very well put.
May I add that 8 or 16 CPUs per node has become a realistic possibility?
Four and eight way(*) Opteron machines are available, up to 128Gbytes
Expect to see more of these machines out there as engineering
workstations or for visualisation and animation/rendering.
Add dual-core CPUs to the mix and you get a very attractive platform.
(*) two quad motherboards, so I guess realistically and 8-way OpenMP is
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