So it looks like they implement two levels of parallelization; npool and
nimage although nimage seems to be defined differently. Running on Np
processors with Nk x Nk x Nk kpoints and Ni images, there must be a nice
ratio of Ni to Nk and Np which is effecient.
"With the pool parallelization,
we distribute different k or q points to different processors. This
method is very efficient for both G and W,
if the number of these points is a multiple of the number of CPUs. The
image parallelization distributes G
vectors used in the linear response and Fourier transform to different
CPU. For the calculation of W, this
parallelization is very efficient because the solution of
the linear-response equation for each G vector is independent of the
other G vectors." from - Lambert, Henry, and Feliciano Giustino. "Ab
initio Sternheimer-GW method for quasiparticle calculations using plane
waves." Physical Review B 88.7 (2013): 075117.
On 2020-02-26 13:43, Paolo Giannozzi wrote:
Parallelization levels do not appear spontaneously: they have to be
implemented, sometimes with a lot of effort. Somewhere in the
documentation of SternheimerGW it must be stated which parallelization
levels are available: presumably, k-point and/or plane-wave
parallelization. The two parallelization levels you mention are
implemented only in a subset of QE codes.
Paolo
On Wed, Feb 26, 2020 at 7:31 PM grayj6 <[email protected]> wrote:
Hello,
I have a calculation of Germanium that I would like to run, but I
am
uncertain as to how to parallelize it. I have a kpt_grid of 4, 4, 4
and
a qpt_grid of 4, 4, 4. The number of bands, num_band is 18. I did
the
scf calculation on a kpoint grid of 8 8 8 0 0 0.
My current submit command is:
mpirun -np 4
/home/grayj6/data/q-e-qe-6.3/SternheimerGW/main/bin/gw.x
-npool 4 < gw.in [1] >gw.out
... but I do not observe any noticeable speed ups when I add in
nbgrp or
ntask parallelization.
Thank you!
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--
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
Links:
------
[1] http://gw.in
[2] http://www.max-centre.eu/quantum-espresso
[3] https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________
Quantum ESPRESSO is supported by MaX
(www.max-centre.eu/quantum-espresso)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
