Growth rate of the mean magnetic energy inside the convection zone (averaged over the kinematic phase of the dynamo) as a function of the grid spacing, Δx. For this analysis, we also simulated the kinematic phase of the dynamo on grids with 384³ and 640³ cells (Δx/L_ref = 5.2 × 10⁻³, and Δx/L_ref = 3.1 × 10⁻³, respectively). Error bars represent three standard deviations, computed over the time series. The expected theoretical scaling for SSD amplification (γ ∝ Re^1/2 ∝ Δx^−2/3) is represented by the black dashed line.