We have studied multiple gluon production at the first impact of pp an
d AA collisions, using large order tree diagrams. We have found that t
his gluon production mechanism at RHIC is more important comparing to
simpler processes considered before. Predictions depend strongly on pe
rturbative cutoff, which we evaluate in a self-consistent way. The est
imated entropy production at first impact at RHIC Au+Au collisions is
comparable or even larger than usual extrapolations. In the LHC case,
earlier estimates are but a first term of divergent series: presumably
, non-perturbative theory has to be developed here.