- 3 VMs running on different machines (same HW) with 1 CPU and 2GB RAM running FreeBSD 10.3

- Connected through a 1Gbps LAN and communicate passwordless through SSH.

- MPICH 3.2_1 installed and working on the three nodes

I've tried to compile and run some code samples that are available for mpich (i.e: http://people.sc.fsu.edu/~jburkardt/c_src/mpi/search_mpi.c)  but I always end up getting worst times running on the 3 nodes that I get running on 1 node alone, even when I can get all 3 nodes to get up to a 100% CPU usage for a couple of minutes.

I know there is network overhead and SSH isn't helping either, so without investing too much time I unfortunately won't have, I'd like to ask you what kind of simple program could I write just for the sake of a proof of concept that running a program with 3 nodes would be faster than running on one.

Maybe dealing with slower operations like disk I/O do counter the inter-node communication?

Many thanks for your kind help

BR

Alex