1. Technology
You can opt-out at any time. Please refer to our privacy policy for contact information.

Power Supply Unit


Photo of a Corsair Enthusiast TX650 V2 ATX12V EPS12V Power Supply

Corsair Enthusiast TX650 V2 ATX12V EPS12V Power Supply

© Corsair

What is a Power Supply Unit?

The power supply unit is the piece of hardware that's used to convert the power provided from the outlet into usable power for the many parts inside the computer case.

The Power Supply Unit is Also Known As

PSU, power supply, power pack, power converter

Important Power Supply Unit Facts

Motherboards, cases and power supplies all come in different sizes called form factors. All three must be compatible to work properly together.

A PSU is not usually user serviceable. For your safety, it's usually wise to never open a power supply unit.

Popular Power Supply Unit Manufacturers

CoolMax, Ultra, (Most power supply units are preinstalled in computer cases)

Power Supply Unit Description

The power supply unit is mounted just inside the back of the case.

The side of the PSU facing outside the case has a male, three pronged port that a power cable, connected to a power source, plugs into. There is also often a power switch and a power supply voltage switch.

Large bundles of colored wires extend from the opposite side of the power supply unit into the computer. Connectors at the opposite ends of the wires connect to various components inside the computer. Some are specifically designed to plug in to the motherboard while others have connectors that fit into fans, floppy drives, hard drives, optical drives, and even some high powered video cards.

Power supply units are rated by wattage to show how much power they can provide to the computer. Since each computer part requires a certain amount of power to function properly, it's important to have a PSU that can provide the right amount. The very handy Thermaltake Power Supply Calculator tool can help you determine how much you need.

Related Video
Install a PC Power Supply

©2014 About.com. All rights reserved.