The ATX +12V connector is a 4-pin connector supplying power at 12V2DC using an 18 Advanced Wireless Group (AWG) wire. This 12-volt connector primarily supplies power for the current converter used to supply the processor with low voltage current while providing a high level of amperage.
ATX 12V power supplies provide power to the motherboard using a 24-pin connector. This connector is the main source of power for the processor and other motherboard components. The connector supplies power at three separate voltage levels: 3.3, 5 and 12V DC.
The peripheral power connector for the ATX 12V power supply is a 4-pin connector commonly used to supply power for older computer drives and case-mounted fans. Newer drivers typically use serial advanced technology attachment (SATA) power connectors.
This power connector provides power for devices compatible with the SATA power specification. Hard drives and optical drives are the most common devices using this type of connector. The SATA power connector uses an 18 AWG wire with a 5-pin connector.