Thank you. Meanwhile I'm continue to get strange errors. RAM seems ok. Apparently I'm getting error only if I use the "-ni 8" option in ph.x. But it's random. Here is the last error:
Program received signal SIGSEGV: Segmentation fault - invalid memory reference. Backtrace for this error: Program received signal SIGSEGV: Segmentation fault - invalid memory reference. Backtrace for this error: #0 0x2AF4EE34C78F #1 0x2AF4EE34CD84 #2 0x2AF4EEFEBE6F #3 0x2AF4EF032058 #4 0x51C509 in cgsolve_all_ #5 0x4E0486 in solve_linter_ #6 0x4BD7F6 in phqscf_ #7 0x45B666 in do_phonon_ #8 0x45758F in MAIN__ at phonon.f90:0 2015-02-20 10:06 GMT+01:00 Andrea Dal Corso <[email protected]>: > 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 > -- ------------------------------------------------------------ Prof. Carlo Nervi [email protected] Tel:+39 0116707507/8 Fax: +39 0116707855 - Dipartimento di Chimica, via P. Giuria 7, 10125 Torino, Italy. http://lem.ch.unito.it/
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