Hi, As I was digging through PWSCF and I noticed that in para.f90, the maximum number of processors is coded to 128. But that there is a switch that can be used to set the maximum to 2048.
-D__QK_USER__ This is going to sound like a dumb question, but is this safe. Will the diagonalization routines on a gamma point calculation have issues if one goes up to 256 or 512. I you had many k-points and spin-polarization that wouldn't so much of an issue I think. Any comments? On 4/26/06, carlo sbraccia <sbraccia at sissa.it> wrote: > Hi, > > beware using the CVS version of PWSCF: the parallel Davidson has not yet > been fully tested and seems to be buggy. > For this reason we are going to disable it until we shall be able to > solve the problem. To avoid the serial bottleneck in the diagonalization > you can use conjugate-gradient. > > carlo > > Andrea Ferretti wrote: > > >Hi everybody, > > > >I am currently running a Copper surface with 140 Cu atoms + a molecule... > >the system has 1642 electrons and (due to metallicity) the calculation is > >performed for 985 bands (few kpt, like 4)... > >due to the 11 electrons for each Cu atom, I have a huge number of bands in > >a (relatively) small cell, and so a (relatively) low number of PWs respect > >to nbnd. > >taking a look at the dimension of wfc, no problem with memory in > >principle, even if, due to the weird > >dimensions of the system, non-scalable memory is quite large, around 1Gb. > > > >on a IBM Sp5 machine I observed a severe limit in the scaling passing from > >32 to 64 procs using both espresso 2.1.x and espresso 3.0... > >( anyway, I succeeded in performing a "relax" calculation for the system > >!!!! ) > > > >as far as I know, this problem might be connected to a serial part in the > >diagonalization which has been parallelized in the current CVS version > >(as already pointed out by Axel)... > >At the moment I am testing this CVS version against my system, I will let > >you know the results as soon as possible... > > > >cheers > >andrea > > > > > > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- Nichols A. Romero, Ph.D. 1613 Denise Dr. Apt. D Forest Hill, MD 21050 443-567-8328 (C) 410-306-0709 (O)
