<div dir="ltr"><div>Dear Matthias Krack,</div><div><br></div><div>As you said I added OMP_NUM_THREADS to mpirun as follows:<br></div><div><br></div><div>'mpirun -np 16 -genv OMP_NUM_THREADS 1'</div><div><br></div><div>I did that for one thread for different number of processors 4, 16 and 32. For 32 it could not perform even one OT after half an hour. The outputs of the three runs done for some minutes are attached. Also, I found that the version of CP2K is 7. Should I use another version?<br></div><div><br></div><br>On Friday, March 8, 2019 at 10:47:01 PM UTC+3:30, Matthias Krack wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;"> <div link="blue" vlink="purple" lang="EN-US"> <div> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1f497d" lang="EN-GB">Hi ?</span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1f497d" lang="EN-GB"> </span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1f497d" lang="EN-GB">The extension “.psmp” implies that you are using an MPI and OpenMP parallel cp2k executable. Did you define the number of OpenMP threads at runtime, e.g. by setting the environment variable OMP_NUM_THREADS? OpenMP usually behaves greedy, if you do not specify the number of threads, i.e. it might create for each MPI process a number OpenMP threads equivalent to the number of available CPU cores, which will easily overload your compute node. This could explain the weird timings, but there might be other reasons as well. You will have to provide a corresponding output file, if you want to have better guesses as an answer.</span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1f497d" lang="EN-GB"> </span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1f497d" lang="EN-GB">Matthias</span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1f497d" lang="EN-GB"> </span></p> <p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> <a href="javascript:" target="_blank" gdf-obfuscated-mailto="H3HQ3LmHBAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a> <<a href="javascript:" target="_blank" gdf-obfuscated-mailto="H3HQ3LmHBAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a>> <b>On Behalf Of </b>Mohammad Shakiba<br> <b>Sent:</b> Freitag, 8. März 2019 19:43<br> <b>To:</b> cp2k <<a href="javascript:" target="_blank" gdf-obfuscated-mailto="H3HQ3LmHBAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a>><br> <b>Subject:</b> [CP2K:11393] Convergence difference with different number of pocessors for an input</span></p> <p class="MsoNormal"> </p> <div> <div> <p class="MsoNormal">Hello everyone,</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">I was using CP2K 6.1.0, compiled with intel 17 and 'psmp' version, for ab initio molecular dynamics. My system contains 87 atoms containing Al, O, C and H (an MOF). I had two major questions, please help me to find their answers.</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">1- When I use 16 number of processors, it takes 2.5 seconds for each OT calculation and when I use 4 processors it takes 2.9 seconds to update OT. When I put the number of processors to 20 it takes 270 seconds (about 5 minutes), put it for 40 it takes 140 seconds and if I put it for 12 processors it takes more than a minute for each update. My question here is just WHY? the following questions are: </p> </div> <div> <p class="MsoNormal">Is there an optimum number of processors? How can I define that? When should we use a high number of processors? I have used command 'mpirun -np $nprocessors cp2k.psmp -i $input -o $output'.</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">2- I used 16 number of processors and 4 number of processors. For 'mpirun -np 16', it does not converge but for 'mpirun -np 4' it converges slightly to the target convergence. I have changed the following commands but the convergence for 16 number of processors did not change. Can you explain why? What would be the solution to obtain convergence for 16 number of processors?</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">Thanks in advance.</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">I summarize the commands in the attached input file:</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">RUN_TYPE MD</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">!FORCE_EVAL</p> </div> <div> <p class="MsoNormal">METHOD Quickstep</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">!QS</p> </div> <div> <p class="MsoNormal">METHOD GPW </p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">EXTRAPOLATION ASPC </p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">PERIODIC NONE</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">PSOLVER MULTIPOLE </p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">SCF_GUESS ATOMIC</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">EPS_SCF 1.0E-6 </p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">PRECONDITIONER FULL_SINGLE_INVERSE ! I also used FULL_ALL</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">MINIMIZER DIIS ! I also used CG but it converges very slightly and sometimes there is no change in the convergence</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">OPTIMIZER BFGS</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">ENSEMBLE NVT </p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal">TYPE NOSE</p> </div> <div> <p class="MsoNormal"> </p> </div> <div> <p class="MsoNormal"> </p> </div> </div> <p class="MsoNormal">-- <br> You received this message because you are subscribed to the Google Groups "cp2k" group.<br> To unsubscribe from this group and stop receiving emails from it, send an email to <a href="javascript:" target="_blank" gdf-obfuscated-mailto="H3HQ3LmHBAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp2k+uns...@googlegroups.<wbr>com</a>.<br> To post to this group, send email to <a href="javascript:" target="_blank" gdf-obfuscated-mailto="H3HQ3LmHBAAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a>.<br> Visit this group at <a href="https://groups.google.com/group/cp2k" target="_blank" rel="nofollow" onmousedown="this.href='https://groups.google.com/group/cp2k';return true;" onclick="this.href='https://groups.google.com/group/cp2k';return true;">https://groups.google.com/<wbr>group/cp2k</a>.<br> For more options, visit <a href="https://groups.google.com/d/optout" target="_blank" rel="nofollow" onmousedown="this.href='https://groups.google.com/d/optout';return true;" onclick="this.href='https://groups.google.com/d/optout';return true;">https://groups.google.com/d/<wbr>optout</a>.</p> </div> </div> </blockquote></div>