[Pw_forum] Question on scaling of Quantum Espresso

Tue Nov 8 18:58:55 CET 2016

Thank you very much again.

Best regards.

2016-11-08 18:27 GMT+01:00 Paolo Giannozzi <p.giannozzi at gmail.com>:

> The number of H\psi products, as well as the number of scf iterations, is
> not directly related to the size of the systems, but larger systems are
> often more difficult to converge than smaller ones, and there may be
> significant differences between "nasty" and "easy" systems.
>
> Paolo
>
> On Tue, Nov 8, 2016 at 4:07 PM, Pablo García Risueño <
> garcia.risueno at gmail.com> wrote:
>
>> Thank you very much again, this help is very useful. In this point I
>> wonder if the (*N*h := number of *H*[image: $ \psi$] products needed by
>> iterative diagonalization) depends on the size of the system, or it is more
>> or less constant for different kinds of systems.
>>
>> Best regards
>>
>> 2016-11-08 12:58 GMT+01:00 Paolo Giannozzi <p.giannozzi at gmail.com>:
>>
>>> There is no similar page for the phonon code, but there is this remark:
>>> "*For phonon calculations, each of the 3Nat modes requires a time of
>>> the same order of magnitude of self-consistent calculation in the same
>>> system (possibly times a small multiple)." *More accurate estimates
>>> depend a lot upon details of the calculation that are not easy to predict
>>> (such as how quickly the system converges)
>>>
>>> Paolo
>>>
>>> On Tue, Nov 8, 2016 at 12:18 PM, Pablo García Risueño <
>>> garcia.risueno at gmail.com> wrote:
>>>
>>>> Thank you very much, prof. Giannozzi, that is what I was looking for.
>>>> Do you know if a similar page exists for the ph.x code?
>>>>
>>>> Best regards
>>>>
>>>> 2016-11-08 11:38 GMT+01:00 Paolo Giannozzi <p.giannozzi at gmail.com>:
>>>>
>>>>> You can find something here:
>>>>> http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_us
>>>>> er_guide/node14.html
>>>>>
>>>>> Paolo
>>>>>
>>>>> On Tue, Nov 8, 2016 at 11:29 AM, Pablo García Risueño <
>>>>> garcia.risueno at gmail.com> wrote:
>>>>>
>>>>>> Dear Federico
>>>>>>
>>>>>> Thank you very much for your message. Unfortunately these tests seem
>>>>>> to measure the computing time as a function of the number of cores, and not
>>>>>> as a function of the number of electrons//plane waves//etc.
>>>>>>
>>>>>>
>>>>>>
>>>>>> 2016-11-08 11:09 GMT+01:00 Federico Iori <federico.iori at u-psud.fr>:
>>>>>>
>>>>>>> Hi Pablo.
>>>>>>>
>>>>>>> Did you have a look at computational centers benchmark test?
>>>>>>>
>>>>>>> I can suggest you
>>>>>>> http://www.quantum-espresso.org/benchmarks/
>>>>>>>
>>>>>>> www.hpc.cineca.it/content/quantumespresso-benchmark
>>>>>>>
>>>>>>> I am not sure they can provide all the info you are looking for
>>>>>>> regarding scaling vs all the parameters of th system thou, but maybe they
>>>>>>> can help somehow.
>>>>>>>
>>>>>>> [image: Université Paris-Sud]
>>>>>>> *Federico IORI*
>>>>>>> Marie Curie Fellow
>>>>>>> Laboratoire de Physique des Solides
>>>>>>> Bâtiment 510 - Rue André Rivière
>>>>>>> 91400 Orsay
>>>>>>>
>>>>>>>
>>>>>>> ------------------------------
>>>>>>> *De: *"Pablo García Risueño" <garcia.risueno at gmail.com>
>>>>>>> *Para: *"PWSCF Forum" <pw_forum at pwscf.org>
>>>>>>> *Enviados: *Martes, 8 de Noviembre 2016 10:50:10
>>>>>>> *Asunto: *[Pw_forum] Question on scaling of Quantum Espresso
>>>>>>>
>>>>>>>
>>>>>>> Dear members of the Espresso community
>>>>>>>
>>>>>>> I would like to know how the total execution time of Quantum
>>>>>>> Espresso (pw.x and ph.x) scales with the different parameters of the
>>>>>>> system, like number of electrons, size of the box, ecutwfc, etc. It would
>>>>>>> be very useful for me to know in which parameters the scaling is linear,
>>>>>>> quadratic or cubic. Of course I can do tests on my own, but they would be
>>>>>>> just partly reliable due to Amdahl's issues.
>>>>>>>
>>>>>>> Thank you very much for your help. Best regards.
>>>>>>>
>>>>>>> --
>>>>>>> --
>>>>>>>
>>>>>>> Dr. Pablo García Risueño
>>>>>>>
>>>>>>> Institut für Physikalische Chemie, Universität Hamburg, Grindelallee
>>>>>>> 117, 20146 Hamburg
>>>>>>>
>>>>>>> Tel. +49 040 42 83 84 82 7
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Pw_forum mailing list
>>>>>>> Pw_forum at pwscf.org
>>>>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Pw_forum mailing list
>>>>>>> Pw_forum at pwscf.org
>>>>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> --
>>>>>>
>>>>>> Dr. Pablo García Risueño
>>>>>>
>>>>>> Institut für Physikalische Chemie, Universität Hamburg, Grindelallee
>>>>>> 117, 20146 Hamburg
>>>>>>
>>>>>> Tel. +49 040 42 83 84 82 7
>>>>>>
>>>>>> _______________________________________________
>>>>>> Pw_forum mailing list
>>>>>> Pw_forum at pwscf.org
>>>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
>>>>> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
>>>>> Phone +39-0432-558216, fax +39-0432-558222
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Pw_forum mailing list
>>>>> Pw_forum at pwscf.org
>>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> --
>>>>
>>>> Dr. Pablo García Risueño
>>>>
>>>> Institut für Physikalische Chemie, Universität Hamburg, Grindelallee
>>>> 117, 20146 Hamburg
>>>>
>>>> Tel. +49 040 42 83 84 82 7
>>>>
>>>> _______________________________________________
>>>> Pw_forum mailing list
>>>> Pw_forum at pwscf.org
>>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>>
>>>
>>>
>>>
>>> --
>>> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
>>> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
>>> Phone +39-0432-558216, fax +39-0432-558222
>>>
>>>
>>> _______________________________________________
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>
>>
>>
>>
>> --
>> --
>>
>> Dr. Pablo García Risueño
>>
>> Institut für Physikalische Chemie, Universität Hamburg, Grindelallee 117,
>> 20146 Hamburg
>>
>> Tel. +49 040 42 83 84 82 7
>>
>> _______________________________________________
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
>
> --
> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>

-- 
--

Dr. Pablo García Risueño

Institut für Physikalische Chemie, Universität Hamburg, Grindelallee 117,
20146 Hamburg

Tel. +49 040 42 83 84 82 7
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