Is MPI Large or Small?

• MPI is large (See this openMPI link)
  • MPI's extensive functionality requires many functions.
  • Number of functions not necessarily a measure of complexity.
• MPI is small. Many parallel programs can be written with just 6 basic functions.
  • MPI_Init– Initialise MPI.
  • MPI_Comm_size– Find out how many processes there are.
  • MPI_Comm_rank– Find out which process I am.
  • MPI_Send– Send a message.
  • MPI_Recv– Receive a message.
  • MPI_Finalize– Terminate MPI.
• MPI is just right
  • One can access flexibility when it is required.
  • One need not master all parts of MPI to use it.