υ_γ (left) and peak-to-peak RV amplitude (right) determined by Gaia SOS compared to VELOCE as a function of logarithmic pulsation period. υ_γ,GDR3 and A_p2p,GDR3 are the values published in table gaiadr3.vari_cepheid as parameters average_rv and peak_to_peak_rv, respectively. Orange points highlight Cepheids for which Gaia used the most adequate template parameters. Blue points show measurements processed using template parameters outside this range. Blue and orange solid lines show linear fits to the respective points; green solid lines show linear fits to the combined data sets. At log P = 1, we find Δυ_γ = 0.51 ± 0.13 km s⁻¹, and a slight trend of 1.03 ± 0.29 km s⁻¹/log P for the orange points. The blue points exhibit a much more significant offset of 1.6 ± 0.2 km s⁻¹ and trend 1.69 ± 0.44 km s⁻¹ / log P. Peak-to-peak amplitudes are generally consistent with a dispersion of approximately 16% and do not exhibit a trend with log P.