Current Settings

User tuning of MPI environment variables can be restricted by the system administrator through a configuration file, hpc.conf. To determine whether such resctrictions are in place on your local cluster use the MPI_PRINTENV (described below) to verify settings. .

In most cases, performance will be good without tuning any environment variables. Nevertheless, here are some performance guidelines for using MPI environment variables. In some cases, diagnosis of whether environment variables would be helpful is aided by Prism profiling with TNF probes, as described in the Prism User's Guide and the Sun MPI Programming and Reference Guide.