24pins

24pins, usually written as 24-pin, refers to the main motherboard power connector used in ATX power supplies for desktop computers. This connector provides the primary power rails and control signals required by the motherboard and its components, including multiple voltage rails and grounding lines, as well as standby and power-good signaling.

The standard consists of two rows of 12 pins in a single housing, with a keyed shape to ensure correct orientation when mated to the motherboard. In practice, the 24-pin main connector often appears as a 20+4 pin configuration, allowing compatibility with older 20-pin boards by using the 4-pin section optionally. The connector carries voltages such as 3.3V, 5V, and 12V, along with grounds and various sense or control lines that inform the system about power status.

History and usage: The 24-pin main power connector was introduced as part of the evolution of the ATX standard in the late 1990s and early 2000s, replacing the earlier 20-pin design to support newer hardware and higher power requirements. Today, the 24-pin connector remains the primary interface between the power supply and the motherboard in most standard ATX systems. It is typically supplemented by additional power connectors for the CPU and other components (for example, EPS12V or PCIe power connectors) as needed by higher-end or modern systems.

Variants and compatibility: While the 24-pin ATX main connector is standard, many power supplies provide a 20+4 pin assembly to maintain compatibility with a wide range of motherboards. Modern boards and PSUs generally assume the 24-pin main connector, with the option to adapt older configurations when required.