Passing large 2d dimentional array in MPI C++

Question

I have a task to speed up a program using MPI. Let's assume I have a large 2d array (1000x1000 or bigger) on the input. I have a working sequential program that divides, so the 2d array into chunks (for example 10x10) and calculates the result which is double for each chuck. (so we have a function which argument is 2d array 10x10 and a result is a double number).

My first idea to speed up:

1. Create 1d array of size N*N (for example 10x10 = 100) and Send array to another process

double* buffer = new double[dataPortionSize];
//copy some data to buffer
MPI_Send(buffer, dataPortionSize, MPI_DOUBLE, currentProcess, 1, MPI_COMM_WORLD);

3. Recieve it in another process, calculate result, send back the result

double* buf = new double[dataPortionSize];
MPI_Recv(buf, dataPortionSize, MPI_DOUBLE, 0, 1, MPI_COMM_WORLD, status);
double result = function->calc(buf);
MPI_Send(&result, 1, MPI_DOUBLE, 0, 3, MPI_COMM_WORLD);

This program was much slower than the sequential version. It looks like MPI needs a lot of time to pass an array to another process.

My second idea:

1. Pass the whole 2d input array to all processes

// data is protected field in base class, it is injected during runtime 
MPI_Send(&(data[0][0]), dataSize * dataSize, MPI_DOUBLE, currentProcess, 1, MPI_COMM_WORLD);

2. And receive data like this

double **arrayAlloc( int size ) {
 double **result; result = new double [ size ];
 for ( int i = 0; i < size; i++ )
 result[ i ] = new double[ size ];
return result;
}

double **data = arrayAlloc(dataSize);
MPI_Recv(&data[0][0], dataSize * dataSize, MPI_DOUBLE, 0, 1, MPI_COMM_WORLD, status);

Unfortunately, I got a bunch of errors during execution:

Those crashes are pretty random. It happened 2 times that the program ended successfully

My third idea:

Pass memory address to all processes, but I found this:

MPI processes cannot read each others' memory, and virtual addressing makes one process' pointer completely meaningless to another.

Does anyone have an idea how to speed up it? I understand that the key thing for speed to is pass array/arrays to processes in an efficient way, but I don't have an idea how to do this.