On Fri, 2015-02-20 at 09:19 +0100, Carlo Nervi wrote: > Dear QE developers, > I would like to have your opinion on the procedure I followed in doing > phonon calculations. > I found that the use of nimages on my machine (8 numa zones) greatly > improves the speed of some calculations, but the first (initialization?) > part of the calculation (epsil=.true., i.e. the Electric Fields > Calculation) is much faster when performed without the use of "-ni 8" > switch in ph.x > > So, I tested the following procedure and apparently worked for a small test > crystal: > > 1) pw.x (vc-relax optimization) without using "-ni" > 2) scf on the optimized structure containing "wf_collect=.true." and using > "-ni 8"
pw.x has no image parallelization, so step 2 should be done without images. The rest should be ok. HTH, Andrea > 3) ph.x containing "only_init = .true." and without using "-ni" > This calculate the electric fields > 4) duplicate the directory _ph0 and copied to _ph1 ... _ph7 (in output > directory) > 5) ph.x containing "recover = .true." and using "-ni 8" > This is the part where I get most of the speedup > 6) ph.x of the input used in 5), but now without using "-ni" > This is to collect the partial data and produce the final .out > > I would greatly appreciate any comments in understanding if this procedure > is correct. > On a small crystal was working, but on a bigger crystal gave error. > Either the procedure is not completely correct or I have to start to look > for a problem in the RAM... > > Thank you, > > Carlo > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum -- Andrea Dal Corso Tel. 0039-040-3787428 SISSA, Via Bonomea 265 Fax. 0039-040-3787249 I-34136 Trieste (Italy) e-mail: [email protected] _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
