This paper presents a comparative performance analysis of LNAs realized in GaAs and GaN/Si technologies in the context of 5G mmWave massive MIMO transceiver. Regardless the choice of architecture for beamforming, a key component of the base station transmitter is the RF frontend. In this paper, we investigate the linear and nonlinear performance in a gain/noise/linearity trade-off for the LNA. The circuits are fabricated using OMMIC technologies and characterized on board over the 24-30 GHz frequency band. Measurements demonstrate that it is interesting to use a GaN in a frontend thanks to its additional advantages in terms of linearity.