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<div class="moz-cite-prefix">Dear Konrad <br>
to my understanding OpenMP can be used when parallelizing
within a multicore node. It needs shared memory between the cores
so can't/shouldn't be used to parallelize across <br>
different nodes. MPI does not need shared memory and can be used
both inside a multicore node and across nodes.<br>
HTH<br>
stefano<br>
<br>
On 19/09/2016 12:01, Konrad Gruszka wrote:<br>
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cite="mid:4cb7cb5a-a0a6-cf00-0634-0d5c8eaf8003@wip.pcz.pl"
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<p>Dear colleagues, <br>
</p>
<p>I'm Writing to our community <span id="result_box"
class="short_text" lang="en"><span>to</span> <span>clarify</span>
<span>once and for all issues with parallel pwscf execution. <br>
</span></span></p>
<p><span id="result_box" class="short_text" lang="en"><span>By
lecture of PWSCF manual, I know that there are several
levels of parallelization, including FFTW and more. At the
same time, I'm quite sure that most of beginner QE users do
not have complicated clusters, but are rather starting with
decent multicore PC's. <br>
</span></span></p>
<p><span id="result_box" class="short_text" lang="en"><span>There
are two main parallel mechanisms (known to me) namely: MPI
and OpenMP. Because I'm using Ubuntu, there is free Hydra
MPI software (mpich) and also free OpenMP. From what I know
(please correct me if this is wrong) MPI software is used
for parallelization within one multicore PC and OpenMP is
used to make parallelization between several PC's. <br>
</span></span></p>
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