[Vagnekman-users] New MPI versions on Ekman

[Michael Schliephake]

Dear Users,

I made several new MPI versions available on Ekman:

Open MPI V. 1.4.4: The latest official stable release from the so-called 
"super stable" series.

Open MPI V.1.5.4: The latest version from the "feature series". It is 
officially a beta release and contains more bug fixes and new features.

These versions are provided for GNU, Intel, and PGI compilers.


MVAPICH2 V.1.7: This MPI library was provided for the first time last 
month. Now I would like to mention that the installation has been fixed 
and the newer Hydra process manager can be used. It allows an easier and 
more sophisticated mapping and pinning of MPI processes to cores. This 
allows more performant job setups that will be improved further together 
with the installed optimization for MPI communication between processes on 
the same node. To give an impression I provided recently the performance 
data in that picture: http://www.pdc.kth.se/~michs/operation/notes.html

This version is supported currently for GNU and Intel compilers.


For the latest list of supported compilers see: 
http://www.pdc.kth.se/resources/software/installed-software/mpi-libraries

Please feel free to contact me in the case of questions or the need of 
support for other compilers.


A technical hint with respect to the use of MPI libraries on Ekman:

For MPI applications using MPI_THREAD_MULTIPLE you will get only the 
performance of IPoIB on the network like it happens now with the Open MPI 
1.4.3 modules. The new MPI libraries are compiled for single-thread use to 
avoid that this happens unnoticed like it is now possible.

The investigation of this issue is ongoing. It focuses of course onto the 
latest versions. Therefore and because there are new features available 
and bug fixes available it is to recommend that you upgrade to the latest 
MPI versions.

Please contact me if you are bound to use MPI with multiple communicating 
threads per process and would like to upgrade the used MPI.


Best regards,
Michael Schliephake