Abstract: The N=8 SO(8) gauged SUGRA in D=4 corresponds to the low-energy dynamics of M-theory when it is compactified on an S^7. A great effort has been put into the construction of solutions of consistent truncations of the maximal theory, such as the STU model. In this talk, I will review both supersymmetric and non-supersymmetric black hole solutions known in the literature, with particular emphasis on the static planar black hole configurations with four charges. For this family, I will present a new thermodynamic stability analysis, due to the fact that the equation of state can be found analytically.