For what it's worth, on our cluster I currently do compile VASP with OpenMPI but we do not include ScaLAPACK because we didn't see a speedup from including it. So far we haven't seen improvements from using OpenMP in VASP or MKL, so we're not doing much with OpenMP either.
On our shared memory machine we will probably do more with OpenMP, especially for MKL.
We're relatively new to VASP, though, so we're eager to hear what works for other people. We're also curious to see how 5.3.x behavior compares with 5.2.x.
On Oct 2, 2012, at 8:11 AM, Noam Bernstein <noam.bernstein_at_[hidden]> wrote:
> Hi - I've been trying to run VASP 5.2.12 with ScaLAPACK and openmpi
> 1.6.x on a single 32 core (4 x 8 core) Opteron node, purely shared memory.
> We've always had occasional hangs with older OpenMPI versions
> (1.4.3 and 1.5.5) on these machines, but infrequent enough to be usable
> and not worth my time to debug.
> However, now that I've got to the 1.6 series (1.6.2, specifically), we're
> getting frequent crashes, mostly but maybe not entirely deterministic. The
> symptom is a segmentation fault in libopmpi.so, someplace under a call to
> PZHEEVX, but in the traceback only routines names in VASP are being printed,
> despite the fact that I have scalapack compiled with -g.
> ScaLAPACK is v 1.8.0, because with v 2.0.2, it completely fails to converge.
> I've tried a couple varieties of the intel compiler (11.1.080 and 18.104.22.1681),
> and a couple of versions of ACML (4.4.0 and 5.2.0). ACML version seems
> not to matter, and the two varieties of ifort give the same type of behavior, but
> crash in different places in the run. When I switch compilers and acml/scalapack
> libraries I recompile everything, except fpr OpenMPI which is always compiled with
> ifort 11.1.080.
> These crashes do not seem to occur on our 2 x 4 core Xeon + IB QDR nodes.
> Has anyone seen anything like this, or has any idea how to get additional
> useful information, for example traceback information so I can figure out what mpi
> routine is having problems?
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