Edge-on view on the α_OX − λ_Edd − M_BH space. The various samples are listed in the legend. The solid line is the best regression as found by Liu et al. (2021), while the dashed lines represent the 1σ dispersion. Quasars with high BH masses and high accretion rates extend the range of the relation. The bulk of our X-ray normal sources follow the extrapolation of the relation calibrated on less luminous sources at lower redshifts.