High face image resolution or low face image for training for face recognition

high face image resolution or low face image resolution for training , in order to get better accuracy for face recognition in a pre-trained model?
thanks

Do progressive training. Say you start with 64x64 image. Train you model and then change the resolution to 128x128 and then train again. In this way you provided your model with 4x times more data and thus more regularization.