Before revision:  For example, our parallel code scaled up to 64 threads on a single node for solving the 3D Poisson equation, discretized with the 7-point stencil on a 1024\times 1024 \times 1024 grid, or \textbf{one billion unknowns.
After revision:  For example, our parallel code scaled up to 64 threads on a single node for solving the 3D Poisson equation, discretized with the 7-point stencil on a 1024\times 1024 \times 1024 grid, or \textbf{one billion unknowns.