All processors, except PE0, receive from their neighbor above and unpack in row 0. Each process only has subgrid. Each process only has subgrid. Performance and Load Balancing Other approaches Data distribution Domain decomposition 17. All processors have entire grid.
Processors work on sub-grids.
Processors broadcast entire sub-grid to all other processors. All processors have only a sub-grid. Processors work on sub-grid. Only boundary data is transferred to neighbors. You have to keep track of your neighbors 18.