What are the enhancements for ATX12V power supplies?
Increased +12 VDC output capability
Motherboard components with unique voltage requirements are increasingly expected to be powered via DC/DC converters off the +12 VDC power supply output. This trend is due primarily to the higher power conversion and transmission efficiencies of +12 VDC relative to +5 VDC or +3.3 VDC.
ATX12V power supplies should be designed to accommodate these increased +12 VDC current requirements and to address associated issues such as cross-regulation, capacitive loading, transient surge tolerance, cable voltage drop and cooling.
New +12 V power connector
To enable the delivery of more +12 VDC current to the motherboard, a new 4-pin receptacle/header combination and the +12 V power connector has been defined. The presence of the +12 V power connector indicates that a power supply is ATX12V; the absence of the +12 V power connector indicates that a power supply is ATX.
This applies to: