  We discuss the crystallization process from the supersaturated melt in terms
of its non-equilibrium properties. In particular, we quantify the amount of
heat that is produced irreversibly when a suspension of hard spheres
crystallizes. This amount of heat can be interpreted as arising from the
resistance of the system against undergoing phase transition. We identify an
intrinsic compression rate that separates a quasi-static regime from a regime
of rapid crystallization. In the former the disspated heat grows linearly in
the compression rate. In the latter the system crystallizes more easily,
because new relaxation channels are opened, at the cost of forming a higher
fraction of non-equilibrium crystal structures. In analogy to a shear-thinning
fluid, the system shows a decreased resistance when it is driven rapidly.
