Top: distribution of the reference T_eff and log g of real spectra (top-left panel) and the ones derived by SP_Ace (top-right panel). Middle: residuals between derived and reference parameters (y-axis) as a function of the reference parameters (x-axis). Bottom: chemical abundances derived by SP_Ace for the same spectra. These spectra have a resolution of R = 2000 and S/N/pixel = 100. The symbols are as in Fig. 23.