Time to compute one time step of a Newtonian simulation for different solvers. In blue, orange, green and red we highlight the time needed to compute a density grid using TSC, an inverse TSC to interpolate the force from grid to particles, a seven-point gradient and the solver respectively. The FULL_FFT method directly computes the force with the kernel described in Eq. (106), hereby removing the need for a finite-derivative gradient part. All timings were done using a single CPU.