<div dir="ltr"><div>Dear Sir,</div><div>Thank you for your response. I have used the following values in the problem:</div><div><br></div><div>dim = 2</div><div>Domain = [0,1]^2</div><div>dt = 0.0075</div><div>Final time = 2dt</div><div>degree = 1</div><div>cells = {500, 500} and global Refine = 1</div><div>overlap = 1</div><div><br></div><div>ISTLBackend_OVLP_BCGS_ILU0 is used as the linear solver.</div><div><br></div><div>I am using a system with Intel Core™ i7-10700 CPU @ 2.90GHz × 1 processor, that has 8/16 number of cores/threads<b>.<br></b></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jan 3, 2022 at 10:18 PM Peter Bastian <<a href="mailto:Peter.Bastian@iwr.uni-heidelberg.de">Peter.Bastian@iwr.uni-heidelberg.de</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
Hello Aswin,<br>
<br>
maybe you could give us a bit more information, e.g.<br>
<br>
- problem size ? and overlap size<br>
- seems to be an inexact subdomain solver?<br>
- what machine did you use? How many cores/nodes ?<br>
<br>
Best,<br>
<br>
Peter<br>
<br>
<div>Am 03.01.22 um 11:09 schrieb Aswin vs:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>Hello, <br>
</div>
<div><br>
</div>
<div>Can somebody suggest me how to get good scalability while
using the overlapping solvers in DUNE. I tried the following
test example in DUNE PDELab, but not getting good scalability.
<br>
</div>
<div>Thank you.<br>
</div>
<div><br>
</div>
<div>$ mpirun -np 1 ./test-heat-instationary-periodic</div>
<div>.</div>
<div>.</div>
<div>.<br>
</div>
STAGE 2 time (to): 1.5000e-02.<br>
=== matrix setup skipped (matrix already allocated)<br>
=== matrix assembly (max) 0.9944 s<br>
=== residual assembly (max) 0.4861 s<br>
=== solving (reduction: 1e-10) === Dune::BiCGSTABSolver<br>
=== rate=0.8397, T=12.57, TIT=0.09524, IT=132<br>
12.68 s<br>
::: timesteps 2 (2)<br>
::: nl iterations 565 (565)<br>
::: lin iterations 565 (565)<br>
::: assemble time 8.0477e+00 (8.0477e+00)<br>
::: lin solve time 5.3414e+01 (5.3414e+01)<br>
<div>---------------------------------------------------------------------------------------<br>
</div>
<div>$ mpirun -np 2 ./testheat-instationary-periodic</div>
<div>.</div>
<div>.</div>
<div>.</div>
<div>STAGE 2 time (to): 1.5000e-02.<br>
=== matrix setup skipped (matrix already allocated)<br>
=== matrix assembly (max) 0.5053 s<br>
=== residual assembly (max) 0.2465 s<br>
=== solving (reduction: 1e-10) === Dune::BiCGSTABSolver<br>
=== rate=0.9268, T=26.95, TIT=0.08895, IT=303<br>
27.05 s<br>
::: timesteps 2 (2)<br>
::: nl iterations 1254 (1254)<br>
::: lin iterations 1254 (1254)<br>
::: assemble time 4.0910e+00 (4.0910e+00)<br>
::: lin solve time 1.1201e+02 (1.1201e+02)</div>
<div>
<div>---------------------------------------------------------------------------------------<br>
</div>
<div>$ mpirun -np 4 ./testheat-instationary-periodic</div>
<div>.</div>
<div>.</div>
<div>.</div>
<div>STAGE 2 time (to): 1.5000e-02.<br>
=== matrix setup skipped (matrix already allocated)<br>
=== matrix assembly (max) 0.271 s<br>
=== residual assembly (max) 0.1318 s<br>
=== solving (reduction: 1e-10) === Dune::BiCGSTABSolver<br>
=== rate=0.9232, T=26.02, TIT=0.0894, IT=291<br>
26.11 s<br>
::: timesteps 2 (2)<br>
::: nl iterations 1249 (1249)<br>
::: lin iterations 1249 (1249)<br>
::: assemble time 2.1746e+00 (2.1746e+00)<br>
::: lin solve time 1.1165e+02 (1.1165e+02)<br>
</div>
<div>
<div>---------------------------------------------------------------------------------------<br>
</div>
<div>$ mpirun -np 8 ./testheat-instationary-periodic</div>
<div>.</div>
<div>.</div>
<div>.</div>
<div>STAGE 2 time (to): 1.5000e-02.<br>
=== matrix setup skipped (matrix already allocated)<br>
=== matrix assembly (max) 0.1772 s<br>
=== residual assembly (max) 0.08259 s<br>
=== solving (reduction: 1e-10) === Dune::BiCGSTABSolver<br>
=== rate=0.9288, T=30.81, TIT=0.09751, IT=316<br>
30.89 s<br>
::: timesteps 2 (2)<br>
::: nl iterations 1329 (1329)<br>
::: lin iterations 1329 (1329)<br>
::: assemble time 1.3485e+00 (1.3485e+00)<br>
::: lin solve time 1.2796e+02 (1.2796e+02)</div>
</div>
</div>
<br clear="all">
<br>
-- <br>
<div dir="ltr">
<div dir="ltr"><font color="#0b5394">Aswin V.S.</font>
<div><font color="#6fa8dc">Research Associate-I</font></div>
<div><font color="#6fa8dc">School of Mathematics</font></div>
<div><font color="#8e7cc3"><b>Indian Institute of Science
Education and Research Thiruvananthapuram</b></font></div>
<div>
<div><span style="font-family:arial,sans-serif"><font color="#351c75">Contact: +91 8089542946 / 7994312946</font></span></div>
<div><span style="font-family:arial,sans-serif;font-size:14px"><b><font color="#351c75">_____________________________________</font></b></span></div>
<div><span style="font-family:arial,sans-serif"><font color="#666666">"The secret of life is not enjoyment
but education through experience."</font></span></div>
<div><font color="#666666"><span style="font-family:Merriweather,Georgia,serif;font-size:14px">― </span><span>Swami
Vivekananda</span></font></div>
</div>
</div>
</div>
</div>
<br>
<fieldset></fieldset>
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