Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |  

This web mail archive is frozen.

This page is part of a frozen web archive of this mailing list.

You can still navigate around this archive, but know that no new mails have been added to it since July of 2016.

Click here to be taken to the new web archives of this list; it includes all the mails that are in this frozen archive plus all new mails that have been sent to the list since it was migrated to the new archives.

Subject: Re: [OMPI users] Need advice on performance problem
From: Ralph Castain (rhc_at_[hidden])
Date: 2013-06-09 18:03:30


Looks to me like things are okay thru 160, and then things fall apart after that point. How many cores are on a node?

On Jun 9, 2013, at 1:59 PM, "Blosch, Edwin L" <edwin.l.blosch_at_[hidden]> wrote:

> I’m having some trouble getting good scaling with OpenMPI 1.6.4 and I don’t know where to start looking. This is an Infiniband FDR network with Sandy Bridge nodes. I am using affinity (--bind-to-core) but no other options. As the number of cores goes up, the message sizes are typically going down. There seem to be lots of options in the FAQ, and I would welcome any advice on where to start. All these timings are on a completely empty system except for me.
>
> Thanks
>
>
> MPI # cores Ave. Rate Std. Dev. % # timings Speedup Efficiency
> ================================================================================================
> MVAPICH | 16 | 8.6783 | 0.995 % | 2 | 16.000 | 1.0000
> MVAPICH | 48 | 8.7665 | 1.937 % | 3 | 47.517 | 0.9899
> MVAPICH | 80 | 8.8900 | 2.291 % | 3 | 78.095 | 0.9762
> MVAPICH | 160 | 8.9897 | 2.409 % | 3 | 154.457 | 0.9654
> MVAPICH | 320 | 8.9780 | 2.801 % | 3 | 309.317 | 0.9666
> MVAPICH | 480 | 8.9704 | 2.316 % | 3 | 464.366 | 0.9674
> MVAPICH | 640 | 9.0792 | 1.138 % | 3 | 611.739 | 0.9558
> MVAPICH | 720 | 9.1328 | 1.052 % | 3 | 684.162 | 0.9502
> MVAPICH | 800 | 9.1945 | 0.773 % | 3 | 755.079 | 0.9438
> OpenMPI | 16 | 8.6743 | 2.335 % | 2 | 16.000 | 1.0000
> OpenMPI | 48 | 8.7826 | 1.605 % | 2 | 47.408 | 0.9877
> OpenMPI | 80 | 8.8861 | 0.120 % | 2 | 78.093 | 0.9762
> OpenMPI | 160 | 8.9774 | 0.785 % | 2 | 154.598 | 0.9662
> OpenMPI | 320 | 12.0585 | 16.950 % | 2 | 230.191 | 0.7193
> OpenMPI | 480 | 14.8330 | 1.300 % | 2 | 280.701 | 0.5848
> OpenMPI | 640 | 17.1723 | 2.577 % | 3 | 323.283 | 0.5051
> OpenMPI | 720 | 18.2153 | 2.798 % | 3 | 342.868 | 0.4762
> OpenMPI | 800 | 19.3603 | 2.254 % | 3 | 358.434 | 0.4480
> _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users