Our present analysis will focus on the S(V)LS mechanism. In the S(V)LS process, silicon nanowires are grown by heating the metal-coated silicon substrate at high temperature in an argon and hydrogen atmosphere. Here, we demonstrate the origin of the driving force needed for the metal supersaturation and calculate the binary phase diagrams of Au-Si nanosystems involved in the growth of nanowires. These new diagrams can be used for other purposes helping to improve the understanding of the physical properties of nanostructures. We also answer the challenging question that many researchers have addressed on whether a minimum size limit of silicon nanowires exists. The nanowire size limit has been evaluated on the basis of thermodynamics and using silicon nanowires obtained via the S(V)LS rather than the VLS mechanism. At 1100°C, the temperature commonly used for the growth of nanowires by the S(V)LS mechanism, it has been found that there is no minimum size limit of nanowires.