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From: Brock Palen (brockp_at_[hidden])
Date: 2006-06-13 10:38:23


Ill provide new numbers soon with the --mac mpi_leave_pinned 1
I'm currious how does this affect real application performace? This
ofcourse is a synthetic test using NetPipe. For regular apps that
move decent amounts of data but want low latency more.
Will that be affected?

Brock Palen
Center for Advanced Computing
brockp_at_[hidden]
(734)936-1985

On Jun 13, 2006, at 10:26 AM, George Bosilca wrote:

> Unlike mpich-gm, Open MPI does not keep the memory pinned by default.
> You can force this by ading the "--mca mpi_leave_pinned 1" to your
> mpirun command or by adding it into the Open MPI configuration file
> as specified on the FAQ (section performance). I think that should be
> the main reason what you're seeing a such degradation of performances.
>
> If this does not solve your problem, can you please provide the new
> performance as well as the output of the command "ompi_info --param
> all all".
>
> Thanks,
> george.
>
> On Jun 13, 2006, at 10:01 AM, Brock Palen wrote:
>
>> I ran a test using openmpi-1.0.2 on OSX vs mpich-1.2.6 from
>> mryicom and i get lacking results from OMPI,
>> at point point there is a small drop in bandwidth for both MPI
>> libs, but open mpi does not recover like mpich, and further on you
>> see a decreese in bandwidth for OMPI on gm.
>>
>> I have attached in png and the outputs from the test (there are
>> two for OMPI )
>> <bwMyrinet.png>
>> <bwOMPI.o1969>
>> <bwOMPI.o1979>
>> <bwMPICH.o1978>
>>
>> Brock Palen
>> Center for Advanced Computing
>> brockp_at_[hidden]
>> (734)936-1985
>>
>>
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>> users mailing list
>> users_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/users
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