Comparison at Z = 0.008, Y = 0.33 and α_ml = 1.90 among the different databases of Table 3. For the STEV database, we selected Y = 0.34 and α_ml = 1.68 as the values among those available that are closest to those of the other databases. The tracks of the Dartmouth databases were interpolated in Z, see text. Upper left panel: theoretical isochrones at t = 12.5 Gyr. Upper right panel: red giant branch tip luminosity. Lower left panel: turn-off luminosity. Lower right panel: helium core mass at the He flash.