CPU cost scaling estimates for 2D (light colours) and 3D (dark colours) hydrodynamics simulations (solid, blue) and MuScaTS syntheses (dashed, red). The scalings are computed according to text and calibrated on a 2D simulation (pseudo-spectral code implemented in Fortran) at N = 1024 for one turnover time (rightmost blue circle). The total CPU cost for simulations at N = 256 and N = 512 (the other two blue circles) is also indicated. Red squares stand for the CPU cost of a few 2D MuScaTS syntheses.