  Dimensional reduction is a key issue in finite temperature field theory. For
example, when following the QCD Free Energy from low to high scales across the
critical temperature, ultrasoft degrees of freedom can be captured by a 3d
SU(3) pure gauge theory. For such a theory a complete perturbative matching
requires four loop computations, which we undertook by means of Numerical
Stochastic Perturbation Theory. We report on the computation of the pure gauge
plaquette in 3d, and in particular on the extraction of the logarithmic
divergence at order g^8, which had already been computed in the continuum.
