[QE-users] Sub optimal performance on 32 core AMD machine

[Carlo Nervi]

While compiling with gcc/gfortran use -march=native option.
With Intel i guess it is -xHost
This will enable the CPU native instruction.
With Epyc I guess a lot depends on the libraries. With gcc I used openblas
and fftw3. On Ryzen they work great.
HTH,
Carlo

Il giorno lun 16 nov 2020 alle ore 18:24 Husak Michal <Michal.Husak at vscht.cz>
ha scritto:

> No. I do no use hyperthreading.
> I had checked both OpenMPI and OpenMP - in outup file ...
> It shows what I set by the launch and enviromental variable correctly.
> If I use more than 4 cores in any way, I get no speed up ...
> ________________________________
> From: users <users-bounces at lists.quantum-espresso.org> on behalf of
> Pietro Delugas <pdelugas at sissa.it>
> Sent: Monday, November 16, 2020 3:42:59 PM
> To: Quantum ESPRESSO users Forum
> Subject: Re: [QE-users] Sub optimal performance on 32 core AMD machine
>
> Hi
> Are you using hyperthreading ?
> If yes, you should try  to use  only 32 cores.  Check the total number of
> processors at the beginning of the run.
> The program makes an intense usage of the cpus so that  hyperthreading  is
> usually inefficient.
> Pietro
>
> Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows 10
>
> From: Michal Husak<mailto:Michal.Husak at vscht.cz>
> Sent: Monday, November 16, 2020 3:19 PM
> To: Quantum ESPRESSO users Forum<mailto:users at lists.quantum-espresso.org>
> Subject: [QE-users] Sub optimal performance on 32 core AMD machine
>
> I
>
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
>


-- 

------------------------------------------------------------
Prof. Carlo Nervi carlo.nervi at unito.it  Tel:+39 0116707507/8
Fax: +39 0116707855      -      Dipartimento di Chimica, via
P. Giuria 7, 10125 Torino, Italy.    http://lem.ch.unito.it/

*ICCC2020 has been postponed at 2022*

ICCC 2022 28 August - 2 September 2022, Rimini, Italy: http://www.iccc2020.com
International Conference on Coordination Chemistry (ICCC 2022)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20201116/81a23423/attachment.html>