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Subject: Re: [OMPI users] Help on the big picture..
From: amjad ali (amjad11_at_[hidden])
Date: 2010-07-22 17:27:26


Hi Cristobal,

Note that the pic in http://dl.dropbox.com/u/6380744/clusterLibs.png
shows that Scalapack is based on what; it only shows which packages
Scalapack uses; hence no OpenMP is there.

Also be clear about the difference:
"OpenMP" is for shared memory parallel programming, while
"OpenMPI" is an implantation of MPI standard (this list is about OpenMPI
obviously).

best
AA.

On Thu, Jul 22, 2010 at 5:06 PM, Cristobal Navarro <axischire_at_[hidden]>wrote:

> Thanks
>
> im looking at the manual, seems good.
> i think now the picture is more clear.
>
> i have a very custom algorithm, local problem of research,
> paralelizable, thats where openMPI enters.
> then, at some point on the program, all the computation traduces to
> numeric (double) matrix operations, eigenvalues and derivatives. thats
> where a library like PETSc makes its appearance. or a lower level
> solution would be GSL and manually implement paralelism with MPI.
>
> in case someone chooses, a highlevel library like PETSc and some low
> level openMPI for its custom algorithms, is there a race for MPI
> problem?
>
> On Thu, Jul 22, 2010 at 3:42 PM, Gus Correa <gus_at_[hidden]> wrote:
> > Hi Cristobal
> >
> > You may want to take a look at PETSc,
> > which has all the machinery for linear algebra that
> > you need, can easily attach a variety of Linear Algebra packages,
> > including those in the diagram you sent and more,
> > builds on top of MPI, and can even build MPI for you, if you prefer.
> > It has C and Fortran interfaces, and if I remember right,
> > you can build it alternatively with a C++ interface.
> > You can choose from real or complex scalars,
> > depending on your target problem (e.g. if you are going to do
> > signal/image processing with FFTs, you want complex scalars).
> > I don't know if it has high level commands to deal with
> > data structures (like trees that you mentioned), but it may.
> >
> > http://www.mcs.anl.gov/petsc/petsc-as/
> >
> > My $0.02
> > Gus Correa
> > ---------------------------------------------------------------------
> > Gustavo Correa
> > Lamont-Doherty Earth Observatory - Columbia University
> > Palisades, NY, 10964-8000 - USA
> > ---------------------------------------------------------------------
> >
> > Cristobal Navarro wrote:
> >>
> >> Hello,
> >>
> >> i am designing a solution to one of my programs, which mixes some tree
> >> generation, matrix operatons, eigenvaluies, among other tasks.
> >> i have to paralellize all of this for a cluster of 4 nodes (32 cores),
> >> and what i first thought was MPI as a blind choice, but after looking
> >> at this picture
> >>
> >> http://dl.dropbox.com/u/6380744/clusterLibs.png ( On the picture,
> >> openMP is missing.)
> >>
> >> i decided to take a break and sit down, think what best suits to my
> needs.
> >> Adittionally, i am not familiar with Fortran, so i search for C/C++
> >> libraries.
> >>
> >> what are your experiences, what aspects of your proyect do you
> >> consider when choosing, is a good practice to mix these libraries in
> >> one same proyect?
> >> _______________________________________________
> >> users mailing list
> >> users_at_[hidden]
> >> http://www.open-mpi.org/mailman/listinfo.cgi/users
> >
> > _______________________________________________
> > users mailing list
> > users_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/users
> >
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