Dependence of the prograde spin-up over time on numerical parameters. Top: variation of the filling factor of the simulation box between 10⁻⁴ ≤ f ≤ 10⁻¹. The runs correspond to N_n = 5000 numerical particles and are run at 5 AU. Bottom: variation of the number of numerical particles 10³ ≤ N_n ≤ 10⁴, computed with a filling factor of f = 10⁻³. The magnitude of prograde spin-up is found to be insensitive to these numerical parameters.