Ratio of the amount of SiO needed to keep the envelope saturated to the total mass added to the planet as a function of the planet mass. The green line shows the nominal model where the critical point of SiO is considered. The orange line shows the case where the critical point is not taken into account. In the nominal case, ΔM_SiO/ΔM_pl becomes larger than unity for M_pl > 2.0 M_⊕. However, ΔM_SiO/ΔM_pl never becomes larger than 2 and the envelope is always saturated in SiO. In the model without T_crit, ΔM_SiO/ΔM_pl reaches unity already at M_pl = 0.8 M_⊕. The key different between the two models, however, is that the amount of SiO needed to keep the envelope saturated in the model without T_c becomes larger than the total mass of the planet for M_pl ≳ 1.0 M_⊕. In this case, the envelope is most likely undersaturated. The feature between 2.1 M_⊕ and 2.5 M_⊕ is likely caused by the inner boundary of the envelope switching between two grid cells.