The evolution of the ATX power supply seems to be a constant process as
computer hardware becomes more powerful and power hungry. First we had
simple units with three basic +3.3V, +5V, and +12V rails, then came
extra features like Power Factor Correction (PFC) to help deliver
cleaner, more efficient power, then came the introduction of SATA hard
drives and the PCI-Express interface spurring on the introduction of a
new ATX 12v 2.0 standard. Among other things, this new power supply
standard includes four extra pins on the main 20-pin ATX motherboard
connector (for a total of 24-pins) and multiple 12V rails for increased
power delivery to new modern power hungry processors and video cards.
Companies then started to develop a modular cabling system that allowed
the user to customize what cables and connections they want and what
they don't. This helped reduce wire clutter inside the case and set
particular products out from the crowd of the usual power supply suspects.
