<div dir="ltr">Hello Dr. Krack, Thank you for responding so quickly. Based on your suggestion, I ran a few benchmarking tests and was able to identify the issue. I realized my SLURM script was getting overwritten during submission, which resulted in all of my calculations running on a single core. I really appreciate your time and guidance. Thank you. Regards, Akanksha </div> <div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Fri, Sep 5, 2025 at 5:05 AM Krack, Matthias <<a href="mailto:matthias.krack@psi.ch">matthias.krack@psi.ch</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg9005553621349154274"> <div lang="en-CH" style="overflow-wrap: break-word;"> <div class="m_9005553621349154274WordSection1"> Hi At a first glance your setup looks fine to me. I don’t understand why it runs so slow. Maybe, you are overcommitting the available resources which often causes a significant slowdown. I suggest to use only one OMP thread per MPI rank. Running your input using an increasing number of CPU cores shows a reasonable scaling up to 64 CPU cores (cp2k v2025.2): <table border="1" cellspacing="0" cellpadding="0" style="border-collapse:collapse;border:none"> <tbody> <tr> <td width="94" valign="top" style="width:70.5pt;border:1pt solid windowtext;padding:0cm 5.4pt"> CPU cores (MPI ranks) </td> <td width="132" valign="top" style="width:99.2pt;border-top:1pt solid windowtext;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:none;padding:0cm 5.4pt"> Average time per MD step [sec] </td> </tr> <tr> <td width="94" valign="top" style="width:70.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0cm 5.4pt"> 8 </td> <td width="132" valign="top" style="width:99.2pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0cm 5.4pt"> 78 </td> </tr> <tr> <td width="94" valign="top" style="width:70.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0cm 5.4pt"> 16 </td> <td width="132" valign="top" style="width:99.2pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0cm 5.4pt"> 40 </td> </tr> <tr> <td width="94" valign="top" style="width:70.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0cm 5.4pt"> 32 </td> <td width="132" valign="top" style="width:99.2pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0cm 5.4pt"> 22 </td> </tr> <tr> <td width="94" valign="top" style="width:70.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0cm 5.4pt"> 64 </td> <td width="132" valign="top" style="width:99.2pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0cm 5.4pt"> 14 </td> </tr> <tr> <td width="94" valign="top" style="width:70.5pt;border-right:1pt solid windowtext;border-bottom:1pt solid windowtext;border-left:1pt solid windowtext;border-top:none;padding:0cm 5.4pt"> 128 </td> <td width="132" valign="top" style="width:99.2pt;border-top:none;border-left:none;border-bottom:1pt solid windowtext;border-right:1pt solid windowtext;padding:0cm 5.4pt"> 12 </td> </tr> </tbody> </table> Best Matthias <div id="m_9005553621349154274mail-editor-reference-message-container"> <div> <div> <div style="border-right:none;border-bottom:none;border-left:none;border-top:1pt solid rgb(181,196,223);padding:3pt 0cm 0cm"> From: 'Akanksha' via cp2k <<a href="mailto:cp2k@googlegroups.com" target="_blank">cp2k@googlegroups.com</a>> Date: Friday, 5 September 2025 at 05:36 To: cp2k <<a href="mailto:cp2k@googlegroups.com" target="_blank">cp2k@googlegroups.com</a>> Subject: [CP2K:21799] Need help with making AIMD simulations faster! </div> Hi, <div> </div> <div> I am trying to run an AIMD simulation of an explicitly solvated system of ~280 atoms at 300 K and 1 bar pressure. However, I have noticed my simulation is very slow (Only reached about 200 fs in a day). I do have a few motion constraints on my solute molecules, which I believe could also make the simulations slower. Each MD step takes about 200 seconds to run with 6-10 SCF iterations. I am new to CP2K and AIMD in general, so I am not sure if this speed is normal. Could anyone please help me figure out if I am missing something or if there are any ways to make these simulations faster? Your help will be very much appreciated. Here are the parameters I am using: 1) CP2K/2024.2 version (mpirun -np 32 -c 4 cp2k.psmp) 2) Anthracene and 2-bromophenol in a DMF box (17*14*14) 2) Calculation started from the last snapshot of a 5 ns classical MD run. 2) PBE-D3(BJ)/DZVP-MOLOPT/GTH 3) ASPC(3) extrapolation 4) DIIS as the OT minimizer with FULL_SINGLE_INVERSE preconditioner </div> <div> 5) Timestep: 0.5 fs 5) CSVR thermostat with 50 fs time constant. I have also attached the full input file and a plot of the constant-of-motion wrt time for your reference. Please let me know if you need more information from me. I would really appreciate any feedback you can provide. Thank you, </div> <div> Akanksha </div> -- You received this message because you are subscribed to the Google Groups "cp2k" group. To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k+unsubscribe@googlegroups.com" target="_blank">cp2k+unsubscribe@googlegroups.com</a>. To view this discussion visit <a href="https://groups.google.com/d/msgid/cp2k/ffb6cc93-0861-43cb-ba6e-047ac09c83e5n%40googlegroups.com?utm_medium=email&utm_source=footer" target="_blank"> https://groups.google.com/d/msgid/cp2k/ffb6cc93-0861-43cb-ba6e-047ac09c83e5n%40googlegroups.com</a>. </div> </div> </div> </div> </div> -- You received this message because you are subscribed to the Google Groups "cp2k" group. 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