>> I found when I took the 432 atom system I sent you, and ran it on >> 128 cores in smp mode >> (1 MPI process/node - 2 GB per process) it did work (-ntg 32 -ndiag >> 121 > > 32 task groups? that's a lot
Yeah - I ran that by mistake. But I figured I'd mention it anyway > > >> as well as -ntg 4 -ndiag 121) > > 4 looks more reasonable in my opinion > Right. >> - the system didn't fit into memory in vn mode (4 mpi processes/ >> node - >> 512 MB per process) > > that job requires approx. 100Mb of dynamically allocated RAM per > process, plus > a few tens of Mb of work space. Why it does not fit into 512Mb is a > mystery, > unless each process comes with a copy of all libraries. If this is > the case, the > maximum you can fit into 512Mb is a code printing "Hello world" in > parallel. > Yeah - I am very curious about this. I was actually *very* surprised when this happened. > By the way: the default number of bands in metallic calculations can > be trimmed > by a significant amount (e.g. 500 instead of 576) > >> I then tried the system in dual mode (2 mpi processes/node - 1 GB >> per process) >> using -ntg 4 and -ndiag 121. In this case, the cholesky error came >> up: > > > the code performs exactly the same operations, independently on how > the MPI > processes are distributed. It looks like yet another BlueGene > weirdness, like this: > http://www.democritos.it:8888/O-sesame/chngview?cn=5777 > http://www.democritos.it:8888/O-sesame/chngview?cn=5932 > that however affected only the internal parallel diagonalization, > not the new > scalapack algorithm. I do not see any evidence that there is > anything wrong > with the code itself. > OK - so perhaps I should try this same run with scalapack enabled instead just to be sure of what happens and that I haven't miscompiled anything. That is only available in the latest CVS versions right? Dave David E. Farrell Post-Doctoral Fellow Department of Materials Science and Engineering Northwestern University email: d-farrell2 at northwestern.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090212/10e2af13/attachment-0001.htm
