, April 24, 2009 2:16:22 PM
Subject: Re: [OMPI users] MPI_Bcast from OpenMPI
Right. So, baseline performance seems reasonable, but there is an odd
spike that seems difficult to explain. This is annoying, but again:
how important is it to resolve that mystery? You can spend a few days
trying to
Second cluster is almost the same features with the previous one
From: Eugene Loh
To: Open MPI Users
Sent: Friday, April 24, 2009 1:26:14 AM
Subject: Re: [OMPI users] MPI_Bcast from OpenMPI
So, the remaining mystery is the 6x or so spike at 128 Mbyte. Dunno.
How important is it to resolve that mystery?
, centOS 4.6,
Second cluster: 2.8 GHz Intel Xeon, 3GBmemory, Fedora core5
Openmpi1.3 is used in both cluster.
From: Eugene Loh
To: Open MPI Users
Sent: Friday, April 24, 2009 1:26:14 AM
Subject: Re: [OMPI users] MPI_Bcast from OpenMPI
Okay. So, going back to
ble) but 131072 KB.
It means around 128 MB.
From: Jeff Squyres
To: Open MPI Users
Sent: Thursday, April 23, 2009 8:23:52 PM
Subject: Re: [OMPI users] MPI_Bcast from OpenMPI
Very strange; 6 seconds for a 1MB broadcast over 64 processes is *way*
too long. Even 2.5 sec at 2MB seems too long
Sorry, I had a mistake in calculation.
Not 131072 (double) but 131072 KB.
It means around 128 MB.
From: Jeff Squyres
To: Open MPI Users
Sent: Thursday, April 23, 2009 8:23:52 PM
Subject: Re: [OMPI users] MPI_Bcast from OpenMPI
Very strange; 6 seconds for a
To: Open MPI Users
Sent: Thursday, April 23, 2009 8:23:52 PM
Subject: Re: [OMPI users] MPI_Bcast from OpenMPI
Very strange; 6 seconds for a 1MB broadcast over 64 processes is *way* too
long. Even 2.5 sec at 2MB seems too long -- what is your network speed? I'm
not entirely sure what you me
Very strange; 6 seconds for a 1MB broadcast over 64 processes is *way*
too long. Even 2.5 sec at 2MB seems too long -- what is your network
speed? I'm not entirely sure what you mean by "4 link" on your graph.
Without more information, I would first check your hardware setup to
see if the
