Power Supply Rails?

[KageSong]

Hey, this might be a little silly, but with all the recent PSU talk, something came to my mind. When I was young and learning to build a computer, my brothers and dad taught me about rails on a power supply. I never understood them well, just something about the 12v rail may be split, so the rated wattage may not be a single rail.

 

Today, building PCs, I never think about things like that. Am I doing something wrong, is it just and old tech thing? Would like to know more about it.

[TrigrH]

Quote

Multi-rail units – Not necessarily better than single-rail units but provide an extra layer of protection by having 12V OCP set lower than total capacity, which is especially relevant for very high capacity units (=>1kW). Pay attention to rails configuration when using with high power draw components to avoid shutdowns.

Source: https://cultists.network/140/psu-tier-list/