Histogram of the S/N, for the 100th order, of the template and each of the 21 individual observations of an M4 star, obtained after the fiber link upgrade of ESPRESSO in mid-2019. In order to compare the impact of the number of observations used to construct the template on its associated uncertainty, one template was built with 8 observations (black curve) and the other with 13 observations (blue curve), selected by the airmass at the start of each observation. For all observations we also highlight the comparison with observations with a S/N of at least 100 for the selected spectral order by filling the bins with the corresponding colour.