Thirdly, the 24V or 48V rail from the AC/DC power supply can be used to power an IBA brick converter, but this time the IBA brick has a 12V output and 12V input POLs are used instead of 5V. Like before, less current has to be distributed from the AC/DC power supply, and there is less 12V bus current on the pcb cards (smaller or thinner pcb traces). The 12V input POLs though are slightly less efficient, usually only a concern with large systems.