[OMPI users] OpenMPI 1.1.4 vs. 1.2

[Michael]

To maintain compatibility with a major HPC center I upgraded(?) from  
OpenMPI 1.1.4 to OpenMPI 1.2 on my local cluster.

In testing on my local cluster, 13 dual-Opteron Linux boxes with dual  
gigabit ethernet, I discovered that my program runs slower using  
OpenMPI 1.2 then OpenMPI 1.1.4 (780.3 versus 402.4 seconds with 3  
processes--tested twice to be certain).

This particular version of my program was designed to minimize the  
amount of communications and the only MPI calls that get used a lot  
are MPI_SEND and MPI_RECV with MPI_PACKED data (so MPI_PACK and  
MPI_UNPACK also get used a lot).

Was there a known problem with OpenMPI 1.2 (r14027) and ethernet  
communication that got fixed later?

The same executable run at the major center seems fine, but they have  
Myrinet.

Michael