[en] We obtain a general expression for the differential entropy per particle (DEP) for three-dimensional Dirac systems as a function of chemical potential, temperature and magnetic field. It is shown that in the presence of magnetic field the dependence of DEP on the chemical potential near a charge neutral point is quite different from the corresponding dependence in graphene. Specifically, we observe a flat region with almost zero DEP near the charge neutral point which grows with the increase of the magnetic field followed then by decreasing oscillations due to contributions from the Landau levels. In contrast, in graphene there is a sharp peak observed for the chemical potential in the temperature vicinity of the Dirac point. (author)