What is MPI?
MPI is a library specification for message-passing, proposed as a standard by a broadly-based committee of vendors, implementors, and users.
- The MPI standard is available.
- MPI was designed for high performance on both massively parallel machines and on workstation clusters.
- MPI is widely available, with both free available and vendor-supplied implementations.
- Test Suites for MPI implementations are available.
- MPICH is a high performance and widely portable implementation of the Message Passing Interface (MPI) standard.
MPI on Theta
- The default MPI on Theta is Cray MPI which is a proprietary implementation from Cray based on the MPICH distribution from Argonne
- Supports Fortran, C, C++
- Integrated within Cray Programming Environment
- IO, collectives, point-to-point and one-sided operations are optimized for the Cray XC architecture
- Highly tunable through environment variables
- Integrated within the Cray programming environment