[Pw_forum] Two binaries for serial and parallel use needed

[Marcel Mohr]

> MM> Dear linux experts
> MM>
> MM> I have newly set up our computer cluster with new mpich2 (1.07)
> MM> and ifort.
> MM> In the last cluster the binary pw.x (compiled with mpich2 1.04) could be
> MM> executed directly or with mpiexec for serial or parallel use,
> MM> respectively.
> MM> Now, this is not possible anymore, I always have to start an smpd
> MM> and run pw.x with mpiexec, even for serial usage.
> MM> It is a bit uncomfortable, so if anyone knows a switch for the compiler,
> MM> or could comment I would greatly appreciate it.

It was a bug in mpich2-1.0.7, with pre release 1.1... it works both ways.

>
> this has to be a "feature" of MPICH, or the way
> you compiled it.
>
> i'm using OpenMPI and don't have that problem.
> if you are after convenience, you should seriously
> consider switching to OpenMPI. particularly on PBS/Torque
> managed clusters, it is _extremely_ convenient
> (job launch through torque, flexible choice of node
> assignment, high efficiency, independence of the
> executable from the underlying communication layer
> (i can compile executable on my desktop with no network
> and run them on myrinet, or infiniband machines directly)).

we are using SGE, but it was a bit tricky to get parallel environments 
working.
On the next cluster I will give it a try.

Cheers
Marcel


>
> cheers,
>   axel.
>
>
> -- 
> =======================================================================
> Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
>   Center for Molecular Modeling   --   University of Pennsylvania
> Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
> tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
> =======================================================================