According to [Michael Frank's video](https://youtu.be/IQZ_bQbxSXk?t=547), there is an architectural overhead of ~500x that people can not get over (IIUC, this overhead only applies for gate based computing models). A reasonable gap between state-of-the-art gate based computing models and Landauer's limit should be 10^2-10^3. On the other side, reversible computing in general has 2-16 times computational overhead at the software level from my using experience. To save energy, reversible computing has to be at least ~10x more energy efficient at the instruction level.