Dear Professor Giannozzi, I understand. Then this half an hour is consistent with my calculations and I will simply have to deal with the computation time Thanks again!
Kind regards Lenz Am Mi., 24. März 2021 um 14:51 Uhr schrieb Paolo Giannozzi < p.gianno...@gmail.com>: > On Tue, Mar 23, 2021 at 10:28 PM Lenz Fiedler <fiedler.l...@gmail.com> > wrote: > > So if I understand you correctly, you did something like >> mpirun -np 18 pp.x -in Fe.pp.ldos.in >> on the nscf data wirh 14x14x14 and got the 560 cube files in 30 minutes? >> > > I computed only ONE cube file, I don't remember for which k-point grid. > You may want to make a few tests with a smaller k-point grid and for a > single energy. Then you can easily guess what will be the needed time for > your complete case. Anyway: if you need so many energies with a dense > k-point grid, it will take a lot of time no matter what. > > Paolo > > This is what I would expect/hope for as well. I will try this and if I >> cannot reproduce it there might be something wrong with my installation. >> >> Kind regards >> Lenz >> >> >> Am So., 21. März 2021 um 16:31 Uhr schrieb Paolo Giannozzi < >> p.gianno...@gmail.com>: >> >>> A LDOS calculation should take more or less the same time as the >>> calculation of the charge density, plus reading, wroting, etc.. I just >>> tried and it took half an hour on 18 processors (CPU cores, not GPUs) >>> >>> Paolo >>> >>> On Wed, Mar 17, 2021 at 5:26 PM Lenz Fiedler <fiedler.l...@gmail.com> >>> wrote: >>> >>>> Dear Professor Giannozzi, >>>> >>>> Thank you so much for your answer. You are right, I did not really >>>> think about the parallelization for the initial SCF calculation, I was more >>>> puzzled by the pp.x calculation. If I understand you correctly, using >>>> something like "pp.x -nk 16" might also help speed up the LDOS calculation >>>> as well? But there also might be an upper limit of how fast this performs >>>> and it could be that I simply have to wait a while to obtain the LDOS? As >>>> in, except for my suboptimal parallelization strategy, the long runtime of >>>> pp.x I observed was not due to wrong usage but simply to computational load >>>> of the problem? >>>> >>>> Kind regards >>>> Lenz Fiedler >>>> >>>> PhD Student (HZDR / CASUS) >>>> >>>> >>>> Am Di., 16. März 2021 um 16:36 Uhr schrieb Paolo Giannozzi < >>>> p.gianno...@gmail.com>: >>>> >>>>> Your supercell is small but you have a high cutoff and a large number >>>>> of k-points, which makes the overall computational load quite heavy. >>>>> Moreover your choice of parallelization is less than optimal: you should >>>>> use both k-point and plane-wave parallelization, something like "mpirun >>>>> -np >>>>> 160 pw.x -nk 16" or so. For reference: I ran your Fe.pw.scf.in input >>>>> in 20' on a small 36-core machine with two (powerful) GPU's. The nscf >>>>> calculation took 1h20' for the calculation and is taking as much time if >>>>> not more to write the files. Also note that not all postprocessing >>>>> calculations are optimized for large runs. >>>>> >>>>> Paolo >>>>> >>>>> On Mon, Mar 15, 2021 at 7:23 PM Lenz Fiedler <fiedler.l...@gmail.com> >>>>> wrote: >>>>> >>>>>> (resent because something went wrong with the header line) >>>>>> >>>>>> Hi users, >>>>>> >>>>>> I am experiencing a problem with pp.x. I want to calculate the LDOS >>>>>> for a 16 Fe atom supercell using a 560 value energy grid and the 3D grid >>>>>> given by the DFT calculation (100x100x100 grid points). I have performed >>>>>> the DFT calculation by first doing a SCF calculation (8x8x8 k-points) and >>>>>> then a non-SCF calculation (14x14x14 k-points) successfully. Now I am >>>>>> trying to do: >>>>>> >>>>>> mpirun -np 160 pp.x -in Fe.pp.ldos.in >>>>>> >>>>>> but the calculation takes way longer than I anticipated. The entire >>>>>> DFT calculation took less than a day, while for the LDOS, after about 12 >>>>>> hours, only 20 tmp files had been written. Am I doing something wrong? Or >>>>>> is this expected? At this rate, calculating the LDOS would take days, >>>>>> which >>>>>> is why I am assuming I am doing something wrong. >>>>>> Please find my output and input files here: >>>>>> >>>>>> >>>>>> https://drive.google.com/drive/folders/1R-m5jlw1bcNxe3nBXjc4dms-IoMMp4Ir?usp=sharing >>>>>> (the pp.out file is from a run where I investigated if a lower number >>>>>> of CPUs helps, but that was slower, as expected.) >>>>>> >>>>>> Kind regards >>>>>> Lenz >>>>>> >>>>>> PhD Student (HZDR / CASUS) >>>>>> _______________________________________________ >>>>>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >>>>>> users mailing list users@lists.quantum-espresso.org >>>>>> https://lists.quantum-espresso.org/mailman/listinfo/users >>>>> >>>>> >>>>> >>>>> -- >>>>> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, >>>>> Univ. Udine, via delle Scienze 206, 33100 Udine, Italy >>>>> Phone +39-0432-558216, fax +39-0432-558222 >>>>> >>>>> _______________________________________________ >>>>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >>>>> users mailing list users@lists.quantum-espresso.org >>>>> https://lists.quantum-espresso.org/mailman/listinfo/users >>>> >>>> _______________________________________________ >>>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >>>> users mailing list users@lists.quantum-espresso.org >>>> https://lists.quantum-espresso.org/mailman/listinfo/users >>> >>> >>> >>> -- >>> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, >>> Univ. Udine, via delle Scienze 206, 33100 Udine, Italy >>> Phone +39-0432-558216, fax +39-0432-558222 >>> >>> _______________________________________________ >>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >>> users mailing list users@lists.quantum-espresso.org >>> https://lists.quantum-espresso.org/mailman/listinfo/users >> >> _______________________________________________ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >> users mailing list users@lists.quantum-espresso.org >> https://lists.quantum-espresso.org/mailman/listinfo/users > > > > -- > Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, > Univ. Udine, via delle Scienze 206, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users
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