Thermodynamic entropy of computer devices

To elucidate several issues relating to the thermodynamics of computations; we performed a simulation of a binary device using a Langevin equation. The simulation confirmed that the minimum energy consumption for a cycle of recording and erasing one-bit of information is kT ln 2 as suggested by Landauer. On the basis of our numerical results, we consider how to estimate the thermodynamic entropy of computational devices. We then argue against the existence of the so-called residual entropy in frozen systems such as ice.