Now I understand that the limit part for current output on a motherboard is partially to do with the pins from teh PSU 12v connectiona nd teh pins in the socket.

But I want to talka bout the buck converter, the main VRM for the CPU power.

I know MOSFETs on boards are rated from 20-50amps. My question is about the inductors(chokes) and how they limit current. i understand that they have 2 current ratings,
Irms which is continuous current, and Isat which is saturation current. I know that once you exceed saturation current the inductor's core becomes flooded...