<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div>For performance use .re2 and the latest master available on GitHub.</div><div><br>On 16 May 2017, at 11:57, "<a href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a>" <<a href="mailto:nek5000-users@lists.mcs.anl.gov">nek5000-users@lists.mcs.anl.gov</a>> wrote:<br><br></div><blockquote type="cite"><div>
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Hi Neks,<br>
<br>
We are carrying out an optimization study on IBM Blue Gene/Q server<br>
of IDRIS using direct-adjoint method. The direct and adjoint equations<br>
are solved using Nek5000. We have observed that for moderate to large <br>
number of<br>
processors Nek5000 spends considerable time in reading the .rea file.<br>
When we reduce the number of processors, the .rea file is read in lesser <br>
time but<br>
the time taken for solver increases. To give an idea, a 3D case for <br>
incompressible flow<br>
with 12000 elements spends 22.132 seconds in reading .rea file if we use<br>
400 processors. If we increase the number of processors to 1000, it <br>
takes more than<br>
90 seconds to read the same .rea file. Can someone provide us a solution on<br>
how to make Nek read the rea file quickly? Would using .re2 file instead <br>
of .rea increase<br>
the performance considering the number of elements is not very large.?<br>
I would like to mention that we are using PPLIST="MPIIO" in the makenek <br>
file.<br>
<br>
Many thanks.<br>
<br>
<br>
<br>
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