PSU Which Cable Goes Where

Which Cable Goes Where? Decoding PSU Cables

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When assembling or upgrading a computer, understanding which cable goes where is crucial for ensuring a stable and functional system. With a myriad of cables connecting various components inside the PC case, it can be daunting for both beginners and seasoned builders. Each cable has a specific role, from powering the motherboard and CPU to connecting storage devices and peripherals. Misplacing a cable or connecting it incorrectly can lead to hardware malfunctions or even permanent damage. This guide will demystify the process, offering a comprehensive overview of which cable goes where in the PSU, such as the 24-pin ATX, 8-pin EPS, PCIe, SATA, and Molex connectors. By the end, you’ll have a clear understanding of where each cable goes and how to ensure each component receives the correct power and data connections, paving the way for a smooth and successful build or upgrade.

Understanding PSU Cable Connections

Understanding PSU cable connections is crucial for ensuring a stable and efficient computer system. Each cable serves a specific purpose in delivering power to vital components such as the motherboard, CPU, graphics card, and storage devices. Proper connection ensures that each component receives the correct voltage and current, minimizing the risk of electrical damage or performance issues. Additionally, correct cable management enhances airflow within the PC case, contributing to better cooling and overall system reliability. By comprehending PSU cable connections, users can optimize their PC’s performance, prevent potential hardware failures, and build or upgrade their systems confidently.

The PSU Cable Puzzle

Building or maintaining a PC can be rewarding, but it comes with challenges. A common source of confusion is determining which PSU cable connects to which component. Misconnecting cables can lead to performance issues or, in the worst-case scenario, damage your hardware. Ensuring each cable is correctly placed is crucial for the system’s stability and longevity. This guide will help you navigate the PSU cable puzzle, ensuring that each component receives the appropriate connections and power, thus avoiding potential pitfalls and ensuring a smooth PC-building experience. So, let’s dive in and make sense of it all. We’ll break down the key components of your PC and explain which PSU cables you need for each. Let’s start with the basics:

1. Motherboard (ATX and EPS Cables)

Motherboards in computer systems typically require two main types of power cables: ATX and EPS.

  1. ATX Power Cable: This cable connects the power supply unit (PSU) to the motherboard to provide general power to the board. It is a large, rectangular connector with 20 or 24 pins, supplying power to various components on the motherboard, such as the CPU, RAM, and expansion slots.
  2. EPS Power Cable: This cable, also known as the CPU power cable, provides additional power directly to the CPU socket on the motherboard. It typically consists of either a 4-pin or 8-pin connector, ensuring stable power delivery to the processor for optimal performance.

2. Graphics Card (PCIe Cable)

Graphics cards in computer systems typically require power from the power supply unit (PSU) using PCIe (Peripheral Component Interconnect Express) cables.

  1. PCIe Power Cable: This cable connects the PSU to the graphics card to provide additional power, especially for high-performance GPUs (Graphics Processing Units). PCIe cables come in various configurations, including 6-pin, 8-pin, or a combination of both, depending on the power requirements of the graphics card.

3. Storage Drives (SATA or Molex Cables)

Storage drives in a computer system are typically connected to the motherboard and power supply unit (PSU) using SATA (Serial ATA) cables and Molex cables, respectively.

  1. SATA Cables: These cables connect storage drives such as SSDs (Solid State Drives) and HDDs (Hard Disk Drives) to the motherboard. SATA cables transmit data between the storage drive and the motherboard, allowing for data transfer and communication.
  2. Molex Cables: These cables provide power from the PSU to the storage drives. Molex cables have connectors that supply power to older drives or peripherals that require Molex power connectors. However, they are less commonly used in modern systems compared to SATA power connectors.

4. Peripherals (SATA, Molex, or 4-Pin Connectors)

Peripherals in a computer system, such as optical drives, fans, and certain types of lighting, may require power connections from the power supply unit (PSU) using SATA, Molex, or 4-pin connectors.

  1. SATA Connectors: Some peripherals, especially newer ones like certain types of optical drives or external storage devices, may utilize SATA power connectors for power supply. SATA connectors offer a more streamlined and efficient power delivery compared to Molex connectors.
  2. Molex Connectors: Older peripherals or certain types of fans and lighting systems may require Molex power connectors for power supply. Molex connectors are characterized by their larger, rectangular shape and are less common in modern systems but are still utilized for backward compatibility or specific peripheral requirements.
  3. 4-Pin Connectors: Some peripherals, particularly fans and certain types of lighting, may use 4-pin connectors for power supply. These connectors are commonly found on case fans and RGB lighting systems and provide power as well as control signals for fan speed or lighting effects.

5. Case (Case Fan Connectors)

Case fans in a computer system typically connect to the motherboard or fan controller using specialized fan connectors.

  1. 3-Pin Connectors: Older case fans often use 3-pin connectors for power and speed control. These connectors feature three pins and provide basic functionality for powering the fan and monitoring its speed.
  2. 4-Pin PWM Connectors: Newer case fans commonly use 4-pin PWM (Pulse Width Modulation) connectors. These connectors allow for more precise control over fan speed by adjusting the voltage supplied to the fan motor. PWM connectors also enable the motherboard to regulate fan speed dynamically based on system temperature.
  3. Molex Connectors: Some case fans may also use Molex connectors for power. These connectors provide a direct power supply from the power supply unit (PSU) and do not support speed control.

Extra Tips and Considerations

Here are some extra tips and considerations when dealing with cables and connections in a computer system:

  1. Cable Management: Proper cable management not only improves airflow and aesthetics but also reduces the risk of cables interfering with components or getting damaged. Use cable ties, routing channels, and cable management features in your case to keep cables organized and out of the way.
  2. Modular Power Supplies: Consider investing in a modular power supply unit (PSU) for easier cable management. Modular PSUs allow you to detach unused cables, reducing clutter inside the case.
  3. Labelling: Labeling cables can be helpful, especially if you have multiple components or a complex setup. Use adhesive labels or cable tags to identify cables and their corresponding connections.
  4. Check Compatibility: Always ensure that cables and connectors are compatible with your components. Refer to the motherboard and PSU manuals to verify the types of connectors supported and the proper installation procedures.
  5. Safety First: Before working on your computer, make sure to power it off and unplug it from the electrical outlet. Handling cables and components while the system is powered can result in electric shock or damage to hardware.
  6. Inspect Cables: Periodically inspect cables for signs of wear, damage, or fraying. Replace any damaged cables to prevent electrical hazards or component failures.
  7. Consult Documentation: When in doubt, refer to the documentation provided with your components or consult online resources and forums for guidance on cable connections and configurations.


In conclusion, understanding the correct placement of PSU cables within a computer system is crucial for optimal performance and safety. Each cable serves a specific function, delivering power to various hardware components such as the motherboard, graphics card, storage drives, and peripherals. By properly routing and connecting cables according to manufacturer guidelines and industry standards, users can ensure efficient power distribution, minimize cable clutter, and maintain adequate airflow for cooling. This attention to detail not only enhances system reliability but also reduces the risk of electrical issues and hardware damage. Ultimately, knowing which PSU cable goes where is key to building a stable and functional computer setup.


Q1: Can I use cable extensions for PSU cables to reach components that are far away?

A: Yes, cable extensions can be used to reach components that are not within the reach of the standard PSU cables. However, ensure that the extensions are of good quality and compatible with your PSU and components.

Q2: What should I do if I accidentally use the wrong cable for a component?

A: If you mistakenly use the wrong cable, power down your PC immediately and disconnect the incorrect cable. Check for any damage to the component, and if it seems unaffected, use the correct cable before powering up again.

Q3: Can I mix and match cables from different PSU manufacturers if they have the same connectors?

A: It’s not recommended to mix and match cables from different PSU manufacturers, even if they have the same connectors. Each PSU may have different pinouts and voltages, which can lead to compatibility issues and potential damage.

Q4: What should I do if I can’t find the right cable for my component in my PSU’s accessories?

A: Contact the PSU manufacturer’s customer support or check their website for replacement cables that are specifically designed for your PSU model.

Q5: Are there any safety precautions I should take while handling PSU cables?

A: When working with PSU cables, ensure that the PC is powered off and unplugged from the electrical outlet. Handle the cables carefully to avoid bending or damaging them, and be mindful of static electricity, which can harm sensitive components.

Last Updated on 23 June 2024 by Ansa Imran


Ansa Imran, a writer, excels in creating insightful content about technology and gaming. Her articles, known for their clarity and depth, help demystify complex tech topics for a broad audience. Ansa’s work showcases her passion for the latest tech trends and her ability to engage readers with informative, well-researched pieces.

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