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How to Choose a PC Power Supply?

A computer power supply is one of the most important components of a computer. It provides the necessary power to all other components in the system. A computer cannot function without power.

In this article, we’ll discuss some of the things to keep in mind when choosing a power supply for your computer and help you choose the right one for your needs.

What is a Power Supply?

Power Supply

A power supply, also known as a PSU (Power Supply Unit), is an electronic device that converts electrical energy from an external power source into the appropriate voltage, current, and frequency required to power and operates electronic devices such as computers, TVs, and smartphones.

Game consoles and other electronic devices.

Power supplies often have multiple outputs with different voltage and current ratings to suit the requirements of different electronic devices.

They may also include various protection features such as overvoltage protection, overcurrent protection, and short circuit protection to ensure the safe and reliable operation of connected equipment tronic devices, and systems.

Types of PSUs

Power supply units (PSUs) come in a variety of form factors, which refer to their physical size, shape, and compatibility with a particular device or system. The most common form factors for PSUs include:

Single Output Power Supply

A single-output power supply is a power supply that provides a single voltage or current output. It is commonly used in various electronic devices and systems to provide stable and steady power to operate circuits or components.

Single-output power supplies are characterized by simplicity and low noise output but are less efficient than switching power supplies.

They typically use a transformer to step down the input voltage and a linear regulator to provide a regulated output voltage or current.

Linear power supplies are typically used in applications that require low noise and minimal interference, such as audio equipment and sensitive electronic circuits.

Slim Type Power Supply

Slim-type power supplies are characterized by their small size and thin profile, which allows them to be easily integrated into space-constrained applications.

They are commonly used in devices such as thin LED/LCD displays, small computers, portable electronics, and other compact electronic systems.

Slim-type power supplies come in a variety of configurations, including linear and switching power supplies, and are typically used to provide stable and regulated power to operate circuits or components in electronic equipment.

Linear low-profile power supplies are known for their simplicity and low-noise output, but they can be less efficient than switching supplies.

Multiple Output Power Supply

A multiple-output power supply is a power supply that provides multiple voltage or current outputs from a single unit. It is commonly used in electronic devices and systems that require different voltages or currents to power various components or subsystems.

Multiple output power supplies are designed to provide stable and regulated power to multiple circuits or components simultaneously.

Multiple output power supplies can come in various configurations, such as linear and switching power supplies, which may have fixed or adjustable outputs.

They are commonly used in applications that require multiple voltages or currents to power different components, such as electronic equipment, embedded systems, industrial automation, and telecommunications systems.

DC-DC Power Supply

A DC-DC power supply, also known as a DC-DC converter, is a power supply that converts one DC voltage level to another DC voltage level. It takes an input DC voltage and provides a regulated output DC voltage above (boost converter) or below (buck converter) the input voltage.

DC-DC power supplies can be used in a variety of configurations, including buck converters, boost converters, buck-boost converters, and isolated converters, among others.

Each type of DC-DC converter has its own advantages and limitations and is suitable for different applications depending on the specific voltage conversion requirements.

DC-DC power supplies are widely used in various electronic devices and systems, including telecommunication systems, industrial automation, automotive electronics, medical equipment, and consumer electronics.

Ultra Thin LED Power Supply

The ultra-thin LED power supply is a power supply specifically designed to power LED (Light Emitting Diode) lighting fixtures in applications where space is limited and a slim form factor is required.

These power supplies are typically compact and low profile, allowing easy integration into slim or tight spaces such as low-profile LED panel lights, LED strips, or other LED lighting applications where available space is limited.

Ultra-thin LED power supplies are designed to provide the DC voltage and current required to drive LEDs, typically requiring a constant current or constant voltage power supply, depending on the type of LED and the specific application.

They are optimized for high efficiency and reliable performance to ensure efficient operation of the LEDs and extend their lifetime.

Power Supply Connector Types

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Power supply units (PSUs) use various connector types to provide power to different components of electronic equipment.

Here are some common connector types used in PSUs:

ATX motherboard connector: This is a 20-pin or 24-pin connector that provides power to a desktop computer’s motherboard.

It is the main connector for supplying power to the motherboard and powering the CPU, RAM, and other components.

CPU Power Connector: Also known as the EPS (Extended Power Supply) connector or ATX12V connector, this is a 4-pin, 8-pin, or 8+4-pin connector that provides power directly to the CPU in desktop computers.

PCIe Power Connectors

These connectors are used to power PCIe (Peripheral Component Interconnect Express) expansion cards, such as graphics cards and other high-performance add-in cards.

SATA Power Connector

The SATA (Serial Advanced Technology Attachment) power connector is used to provide power to SATA storage devices such as hard disk drives (HDD), solid-state drives (SSD), and optical drives.

Molex Power Connectors

Molex connectors, also known as peripheral power connectors, are widely used in older systems and some peripherals.

The power components like fans, pumps, and some older HDDs and optical drives. Molex connectors have a four-pin rectangular shape.

Berg (Floppy) Power Connector

A Berg connector, also known as a floppy power connector, is a small four-pin connector commonly used to provide power to floppy drives.

GPU Power Connector

Some high-end graphics cards may require additional power beyond that provided by the PCIe slot and may have their own power connector.

These connectors can be in the form of 6-pin, 8-pin, or 6+2-pin PCIe power connectors and are used to provide additional power to the graphics card for stable operation.

Other Factors to Consider

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Properly matching your power supply to your computer case and using compatible cabling is essential when building a PC. Beyond ensuring compatibility, there are other considerations that will affect the success and user satisfaction with their choice of PSU.


Fan noise is an issue for many users. When a power supply starts pumping out a lot of power, it heats up. Overheating can cause the PSU’s fan speed to increase significantly and become very loud.


The connectors of a power supply unit (PSU) are essential to its operation, and related cables also provide convenient cable management and personalization.

All power wiring comes in three varieties:

  • Modular,
  • Semi-modular,
  • Pre-installed.

Modular cables allow the user to choose which ones they need to connect the PSU to their components, semi-modular PSUs come with some cables and plugs prewired into them, while pre-installed designs use permanently wired connections.

Modular power supplies offer an efficient and customizable solution for computer users. They allow users to connect the minimum number of cables to each device, saving space and decreasing clutter.

The modular design of these devices also enables great cable management, as well as the option to personalize with custom cables.

Pre-installed, non-modular PSUs have all their cables already installed on the power supply and are not able to be taken out.

These units make for a straightforward installation, but can often lead to tangled cables and extra connectors that add clutter inside the case.

A semi-modular power supply offers the benefits of both traditional and modular supplies. It comes with some cables pre-installed, but it leaves space for additional cables to be added as needed.

This makes a semi-modular power supply a great choice for those who need flexibility when building their PC.

How to Choose a Power Supply?

Selecting an appropriate power supply unit (PSU) for your computer is critical for its optimal functioning. Be sure to study the specifications in detail and confirm compatibility with other components.

Here is a brief summary of how to choose a power supply:

  • Determine how much power your CPU, GPU, and other devices need to run properly.
  • Make sure your PSU connections match your other components.
  • Double-check to make sure your PSU is the right one for your situation.
  • Consider long-term factors such as acoustics, cable management, and upgradeability.


The right PSU ensures that your system receives consistent and reliable power, which is essential for all components to function properly.

When selecting a PSU, it’s important to consider factors such as power, efficiency, form factor, and connector type to ensure compatibility with your system and future upgrades.

A well-chosen PSU will provide your system with stable and reliable power, ensuring smooth and efficient operation for years to come.