Maximum amount of data that can be sent using MPI::Send

Question

With the syntax for MPI::Isend as

MPI::Request MPI::Comm::Isend(const void *buf, int count, 
              const MPI::Datatype& datatype, 
                       


        

Answer 1

The maximum size of an MPI_Send will be limited by the maximum amount of memory you can allocate

and most MPI implementations supportsizeof(size_t)