Careful selection of the upper and lower MOSFETs will determine the overall efficiency of the buck converter. The on-resistance of the power MOSFETs and switching losses will affect the overall efficiency. The compensation components must be selected to ensure that the design meets the stability criteria over the required operating conditions. Placement of the external components can also affect the performance of the power supply. Designers must use an optimal layout to minimize noise and maximize system efficiency. This process must be repeated for each power rail. If there are thirty point-of-load (POL) power rails in the system, the process must be repeated thirty times, which can quickly become a daunting task for a power subsystem designer.