University of Illinois at Urbana-Champaign, Department of Mechanical and Industrial Engineering1206 West Green Street, Urbana, IL, 61801(February 1, 2008)We compare time-dependent solutions of different phase-field models for dendritic solidificationin two dimensions, including a thermodynamically consistent model and several ad hoc models.The results are identical when the phase-field equations are operating in their appropriate sharpinterface limit. The long time steady state results are all in agreement with solvability theory. Nocomputational advantage accrues from using a thermodynamically consistent phase-field model.PACS Numbers: 81.10.Aj, 05.70.Ln, 64.70.Dv, 81.30.Fb