I'm curious if that resolved the issue.
David Singleton wrote:
http://www.open-mpi.org/faq/?category=running#oversubscribing
On 12/03/2010 06:25 AM, Price, Brian M (N-KCI) wrote:
Additional testing seems to show that the problem is related to
barriers and how often they poll to determine whether or not it's
time to leave. Is there some MCA parameter or environment variable
that allows me to control the frequency of polling while in barriers?
From: users-boun...@open-mpi.org [mailto:users-boun...@open-mpi.org]
On Behalf Of Price, Brian M (N-KCI)
Sent: Wednesday, December 01, 2010 11:29 AM
To: Open MPI Users
Cc: Stern, Craig J
Subject: EXTERNAL: [OMPI users] Open MPI vs IBM MPI performance help
OpenMPI version: 1.4.3
Platform: IBM P5, 32 processors, 256 GB memory, Symmetric
Multi-Threading (SMT) enabled
Application: starts up 48 processes and does MPI using MPI_Barrier,
MPI_Get, MPI_Put (lots of transfers, large amounts of data)
Issue: When implemented using Open MPI vs. IBM's MPI ('poe' from HPC
Toolkit), the application runs 3-5 times slower.
I suspect that IBM's MPI implementation must take advantage of some
knowledge that it has about data transfers that Open MPI is not
taking advantage of.
Any suggestions?
