RE: AMBER: Question about MPI-IO

From: Ross Walker <>
Date: Mon, 11 Jun 2007 16:16:02 -0700

> petascale machines and/or if you routinely run off NSF mounted disks
> and/or if you run a really large system. We do worry about I/O

Note if you are writing to a NFS filesystem MPI/IO likely won't help you
anyway. If anything it will likely just slow things down. In this situation
your only real option is to use binary trajectory files or reduce the
frequency of trajectory writing to get the I/O load down.

MPI/IO will only really help you if you have a decent SAN connected to each
of your nodes with a decent parallel filesystem like GPFS or Lustre.

Just my 2c...


|\oss Walker

| HPC Consultant and Staff Scientist |
| San Diego Supercomputer Center |
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Received on Wed Jun 13 2007 - 06:07:26 PDT
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