Errors in the RV measurement of single observations vs. S/N at 550 nm for HARPS (green points, only observations of MS faint stars), SOPHIE (red points, all measurements, typically TO and evolved stars) and HET (black points, all measurements, mostly TO and evolved stars) are presented. The precision of the majority of the measurements for the faint stars is between 10 and 20 m   s^-1. For HARPS, systematic dominates the uncertainty at 8 m   s^-1 for S/N’s above  ~13 in EGGS mode. For our SOPHIE observations we estimate that systematic effects (not included in the figure) dominate the error below  ~12 m   s^-1. The V mag range of the star sample for SOPHIE and HET is brighter than HARPS.