The power supply unit (PSU) is a critical component in any computer system. It converts the alternating current (AC) from your wall outlet into direct current (DC) that your computer components can use. Without a functioning PSU, your computer cannot operate. It supplies power to all internal components, including the motherboard, CPU, graphics card, storage drives, and peripherals.

Types of Power Supplies

There are various types of power supplies, each designed to fit specific needs:

Non-Modular PSU: All cables are permanently attached. This type is cost-effective but can lead to cluttered cable management.

Modular PSU: Cables can be attached or detached as needed, allowing for better airflow and easier cable management.

Semi-Modular PSU: A hybrid between non-modular and modular, with some cables fixed and others detachable.

Power Supply Connectors

PSUs come with various connectors to power different components

ATX Connector: A 24-pin connector that supplies power to the motherboard.

EPS Connector: Typically a 4 or 8-pin connector that provides additional power to the CPU.

PCI Express Connectors: 6, 8, or 6+2 pin connectors that supply power to graphics cards.

SATA and Molex Connectors: Used for powering storage drives and other peripherals.

Efficiency and 80 Plus Certification

The efficiency of a PSU is crucial for energy consumption and heat generation. The 80 Plus certification program rates PSUs based on their efficiency, with levels including Bronze, Silver, Gold, Platinum, and Titanium. A higher certification indicates better efficiency, meaning less energy is wasted as heat.