Which MPI collective routine is used to send data from one processor to all others?MPI_ReduceMPI_BcastMPI_GatherMPI_Allreduce

Breakdown the Problem

We need to identify which MPI collective routine is used to send data from one processor to all others among the options provided.

Relevant Concepts

1. MPI_Reduce: This routine reduces data from all processes to a single process.
2. MPI_Bcast: This routine broadcasts data from one processor to all others.
3. MPI_Gather: This routine collects data from all processes to a single process.
4. MPI_Allreduce: This routine combines data from all processes and distributes the result back to all processes.

Analysis and Detail

• MPI_Reduce does not send data to all processes; it reduces data to one.
• MPI_Bcast sends data from a single source to all other processes.
• MPI_Gather collects data rather than broadcasting it out to all.
• MPI_Allreduce distributes the reduced result back to all processes, but it does not send raw data from one to all.

Verify and Summarize

The correct routine to send data from one processor to all others is MPI_Bcast.

Final Answer

The MPI collective routine used to send data from one processor to all others is MPI_Bcast.