A key feature of the pC++ programming system is its ability to transparently and efficiently support scaling of problem size and machine size. Clearly, the dominant performance concern is pC++'s ability to achieve scalable performance. As the problem size increases, pC++ should support increased processing efficiency. In response to increasing numbers of processors, pC++ should demonstrate good speedup. Scalability results for shared and distributed versions of the pC++ system are given below. We also provide comparisons to Fortran results where appropriate.