High Performance Computing 1
Parallel MG
•The processor indicated by the pink dotted line requires certain grid point data from its neighbors to execute the algorithm. For example, to update its own (blue) grid points for P(5), the processor requires 8 blue grid point values from its N, S, E, and W neighbors, as well as single blue grid point values from its NW, SW, SE and NE neighbors. Similarly, updating the (red) grid points for P(4) requires 4 red grid point values from the N, W, E and W neighbors, and one each from the NW, SW, SE and NE neighbors. This pattern continues until each processor has only one grid point. After this, only some processors participate in the computation, requiring one value each from 8 other processors.