<html>#2187: comet files in simfactory use one MPI rank per node
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<tr><td style='text-align:right'> Reporter:</td><td>Roland Haas</td></tr>
<tr><td style='text-align:right'> Status:</td><td>open</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td></td></tr>
<tr><td style='text-align:right'> Version:</td><td>development version</td></tr>
<tr><td style='text-align:right'> Type:</td><td>enhancement</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>minor</td></tr>
<tr><td style='text-align:right'>Component:</td><td>SimFactory</td></tr>
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<p>Changes (by Roland Haas):</p>
<p><table>
<tr><td>status:</td><td>open (was new)</td></tr>
</table></p>
<p>The current (<a href="https://bitbucket.org/simfactory/simfactory2/src/master/mdb/machines/comet.ini" rel="nofollow" class="ap-connect-link">https://bitbucket.org/simfactory/simfactory2/src/master/mdb/machines/comet.ini</a>) uses 1 MPI rank per node:</p>
<div class="codehilite"><pre><span></span>max-num-threads = 24
num-threads = 24
</pre></div>
<p>This is usually not the best way to set things up, I would eg have expected that the default choice would be something like 1 MPI rank per NUMA domain.
Given that, unless limited by communication overhead, we seem to obtain fastest per-node performance when using only MPI and no OpenMP (about a factor of 50% speedup on my 12 core workstation with 2 NUMA domains) if anyone is using Comet for production work and wants to contribute their machine description file that would be great.</p>
<p><strong>Keyword:</strong> None</p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2187/comet-files-in-simfactory-use-one-mpi-rank'>https://bitbucket.org/einsteintoolkit/tickets/issues/2187/comet-files-in-simfactory-use-one-mpi-rank</a></p>
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