Re: Linux and system area networks

[Bogdan Costescu]

On Wed, 27 Jun 2001, Pekka Pietikainen wrote:

> Providing a wrapper library for use with Infiniband and the current
> SAN boards like WSD would probably be a useful exercise, but to really get
> good performance (especially latency-wise) you probably want to use
> something like MPI. For many applications a wrapper will be enough, though.

I'm sorry, but I don't understand your reference to MPI here. MPI is a
high-level API; MPI can run on top of whatever communication features
exists: TCP/IP, shared memory, VI, etc.
MPI (as well as other "standards" for parallel programming - PVM, OpenMP)
came from the need to have a common interface, not to have all parallel
programs include specific code to deal with TCP/IP, shared memory, VI,
etc. whenever they were available. Instead, MPI serves as a middle-man
between them and the parallel programs. So, MPI cannot be faster than the
underlying communication features.

Sincerely,

Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
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