# Computing

MPI library

Availability:
Instructions for users:

Load the appropriate mpi/openmpi module for your chosen compiler. Compile your code using the OpenMPI provided compiler wrappers: mpicc, mpif90, mpicc++, mpif77. If you use the Intel version of OpenMPI, watch out for the fact that the -fast option turns on static linking which will not work. OpenMPI can be linked statically but our installation isn't set up for it, and it's not usually a good idea to link statically with OpenMPI anyway. Use -O3 -ipo instead.

To run your code on the workstations use the mpirun command. Most people probably just want mpirun -np 2 ./my_program. If you are lucky enough to have access to two or more PCs to run on have a look at the manpage for mpirun, or try mpirun -np 4 -H pc1,pc2 ./my_program. You will need to have set up passwordless login from one PC to the other using ssh public key authentication.

Licence Details:
Documentation:

There are manpages. There is a good online FAQ.

Source:

Very easy to compile but takes ages. You need a few extra flags to ensure it finds its libraries at runtime. You need to do versions for GNU, Intel, and PGI compilers:

./configure  --prefix=/usr/local/shared/$(lsb_release -si | tr [A-Z] [a-z])-$(lsb_release -rs)/x86_64/$(basename$(pwd)) --enable-mpirun-prefix-by-default  --with-wrapper-ldflags="-Wl,-rpath -Wl,/usr/local/shared/$(lsb_release -si | tr [A-Z] [a-z])-$(lsb_release -rs)/x86_64/$(basename$(pwd))/lib"  && make && make install

module add icc ./configure CC=icc CXX=icpc F77=ifort FC=ifort \ --prefix=/usr/local/shared/suse-11.1/x86_64/openmpi-1.3.1-intel11  \ --enable-mpirun-prefix-by-default \ --with-wrapper-ldflags="-Wl,-rpath -Wl,/usr/local/shared/suse-11.1/x86_64/openmpi-1.3.1-intel11/lib"
make
make install 

Note compiler flags for pgi

 module add pgi ./configure CC=pgcc CXX=pgc++ F77=pgf77 FC=pgf90 CFLAGS="-tp=x64" CXXFLAGS="-tp=x64" FCFLAGS="-tp=x64" \ --prefix=/usr/local/shared/suse-11.1/x86_64/openmpi-1.3.1-pgi80  \ --enable-mpirun-prefix-by-default \ --with-wrapper-ldflags="-Wl,-rpath -Wl,/usr/local/shared/suse-11.1/x86_64/openmpi-1.3.1-pgi80/lib" make make install

### System status

System monitoring page

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