./configure -mpp or -mppx??

[Peter Knowles]

At Tue, 12 Feb 2002 14:13:42 +0800 (CST),
Jen-Shiang Kenny Yu wrote:
> 
> Dear Sir/Madam,
> 
> 	I would like to learn about the proper configure parameters for MOLPRO
>  2002.1 with a Linux Cluster having 10 nodes, 2 SMP CPUs per node. What is
>  the difference between ./configure -mpp and -mppx? 

-mppx is experimental and, for the moment, undocumented. It provides
'trivial' parallelism, where different processors each execute
different electronic structure calculations in serial. You probably
want -mpp.

>  	Also, is it possible to execute parallel computation on Linux
>  with GA only and without MPI? I have tried all the different kinds of
>  combinations, but found that MPI is required for any sitiations, e.g,
>  the answer to
>  
>  Do wish to link molpro against tcgmsg-mpi rather than plain tcgmsg?
>  
>  must be yes. Otherwise the following error will pop-out while running
>  make:
>  
>  GNUmakefile:36: *** Cannot find 'parallel' command in PATH.  Stop.

Yes. You need to familiarize yourself with GA (see the file g/README
in the GA source tree) to realize that the tcgmsg flavour has an
executable 'parallel' which starts up the parallel processes (like
mpirun). Molpro makes use of this, and must be able to find it at
configure time. tcgmsg is recommended wherever it can be used, which
is most SMP systems, and clusters connected by ethernet. Where special
drivers are needed for the interconnect, e.g. Myrinet, these are often
provided only through an MPI library, and then you have to use
tcgmsg-mpi.

--
Prof. Peter J. Knowles              
Email P.J.Knowles at bham.ac.uk  Phone +44-121-414-7472  Fax +44-121-414-7471
School of Chemical Sciences, University of Birmingham, Birmingham, B15 2TT, UK
WWW http://www.tc.bham.ac.uk/~peterk/