I am sorry for the delay in replying; this week got a bit crazy on me.

I'm guessing that Open MPI is striping across both your eth0 and ib0 interfaces.

You can limit which interfaces it uses with the btl_tcp_if_include MCA param.  
For example:

    # Just use eth0
    mpirun --mca btl tcp,sm,self --mca btl_tcp_if_include eth0 ...

    # Just use ib0
    mpirun --mca btl tcp,sm,self --mca btl_tcp_if_include ib0 ...

Note that IPoIB is nowhere near as efficient as native verbs, so you won't get 
nearly as good performance as you do with OMPI's openib transport.

Note, too, that I specifically included "--mca btl tcp,sm,self" in the above 
examples to force the use of the TCP MPI transport.  Otherwise, OMPI may well 
automatically choose the native IB (openib) transport.  I see you mentioned 
this in your first mail, too, but I am listing it here just to be 
specific/pedantic.



On May 22, 2014, at 3:30 AM, Bibrak Qamar <bibr...@gmail.com> wrote:

> Hi,
> 
> I am facing problem in running Open MPI using TCP (on 1G Ethernet). In 
> practice the bandwidth must not exceed 1000 Mbps but for some data points 
> (for point-to-point ping pong) it exceeds this limit. I checked with MPICH it 
> works as desired. 
> 
> Following is the command I issue to run my program on TCP. Am I missing 
> something?
> 
> -bash-3.2$ mpirun -np 2  -machinefile machines -N 1 --mca btl tcp,self 
> ./bandwidth.ompi 
> --------------------------------------------------------------------------
> The following command line options and corresponding MCA parameter have
> been deprecated and replaced as follows:
> 
>   Command line options:
>     Deprecated:  --npernode, -npernode
>     Replacement: --map-by ppr:N:node
> 
>   Equivalent MCA parameter:
>     Deprecated:  rmaps_base_n_pernode, rmaps_ppr_n_pernode
>     Replacement: rmaps_base_mapping_policy=ppr:N:node
> 
> The deprecated forms *will* disappear in a future version of Open MPI.
> Please update to the new syntax.
> --------------------------------------------------------------------------
> Hello, world.  I am 1 on compute-0-16.local
> Hello, world.  I am 0 on compute-0-15.local
> 1    25.66    0.30
> 2    25.54    0.60
> 4    25.34    1.20
> 8    25.27    2.42
> 16    25.24    4.84
> 32    25.49    9.58
> 64    26.44    18.47
> 128    26.85    36.37
> 256    29.43    66.37
> 512    36.02    108.44
> 1024    42.03    185.86
> 2048    194.30    80.42
> 4096    255.21    122.45
> 8192    258.85    241.45
> 16384    307.96    405.90
> 32768    422.78    591.32
> 65536    790.11    632.83
> 131072    1054.08    948.70
> 262144    1618.20    1235.94
> 524288    3126.65    1279.33
> 
> -Bibrak
> _______________________________________________
> users mailing list
> us...@open-mpi.org
> http://www.open-mpi.org/mailman/listinfo.cgi/users


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