One of the most important aspects of parallel computing is the communication between processes since it has tremendous impact on overall performance of this method of computing. Consequently, it is important to implement the parallel code in a way that communications between processes are taking place in a most efficient way. In this study we want to investigate the effect of domain subdivision, 1-D or 2-D, on performance of parallel computing. In this regard, the Poisson equation is solved as a test problem using finite difference method with both 1-D and 2-D domain subdivisions. Both aforementioned methods show good speedup. Although in most cases the grid-structured communication show slightly better performance, the overall performance of 2-D domain subdivision does not indicate the superiority of this method.