On Tue, Mar 23, 2021 at 10:28 PM Lenz Fiedler <[email protected]> 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 < > [email protected]>: > >> 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 <[email protected]> >> 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 < >>> [email protected]>: >>> >>>> 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 <[email protected]> >>>> 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 [email protected] >>>>> 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 [email protected] >>>> https://lists.quantum-espresso.org/mailman/listinfo/users >>> >>> _______________________________________________ >>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >>> users mailing list [email protected] >>> 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 [email protected] >> https://lists.quantum-espresso.org/mailman/listinfo/users > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list [email protected] > 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
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