A numerical model was implemented to analyze the thermodynamic performance of the co- and counter-flow operations of an anode-supported direct internal reforming (DIR) planar solid oxide fuel cell (SOFC). This developed model was validated by comparing with experimental and simulated results taken from the literature. The model is capable of capturing the detailed distribution of the local temperatures, species concentrations, current density, and polarization losses in streamwise direction. Energy and exergy concepts were used to evaluate the DIR-SOFC performance under co- and counter-flow operations. The study indicates the energy and exergy efficiencies of DIR-SOFC performance under co-flow operation are more sensitive to the increase of current density than that under counter-flow operation. Particular attention was paid to cell temperature profiles to avoid mechanical failure due to high thermal stresses. The result shows that the material constraints need to be considered as well as the energy and rational efficiencies in evaluating the performance of SOFC. The preferred flow configuration can be changed depending on the cell geometry and operation conditions if we consider the material constraints. (C) 2011 Elsevier B.V. All rights reserved.