Parameters to Consider When Choosing a PC Power Supply

by · Critical Hit

How much power do you need for your PC build?

To assess how much power exactly your PC PSU needs, you should evaluate a few key factors. First, summarize the power consumption of all your PC components. Include everything, even the less power-demanding parts – CPU, GPU, motherboard, RAM, and storage devices. When you get a clear figure, add an extra 20–30 % power capacity for stable system operation and a room for further upgrades. As a rule, most modern gaming systems require from 500W to 850W of power. In a case, you use a top-tier configuration with dual GPUs, you may need 1000W and above. 

How important is power supply efficiency (80 PLUS® certification)?

80 PLUS® certification plays the same important role as the power capacity of your PSU. It shows how much power goes directly to your PC components and what parts of it are lost as heat. 80 PLUS® efficiency certification is a guarantee that your PSU will operate effectively with more economy for your electricity bills, and what’s more important – stably. It’s a great assistant for the workstation power supply operation and other PC power supply tasks.

Power supply form factor and size

Power supply form factor and size determine whether it will physically fit your PC case and whether it is compatible with other components. The most widely used and popular standard today for a new power supply for a PC is the ATX format. It’s compatible with most desktop builds and popular among professional PC users around the world. Also, there are power supplies with SFX format that are also compatible with powerful but compact PC builds. Choosing the right form factor ensures easy installation, effective cooling, and proper cable management at once.

What types of connectors should your power supply have?

These are the core connectors integrated into each power supply unit for PC:

  1. 24-pin ATX – main power supply connector for the motherboard.
  2. 4+4-pin EPS / CPU – for the processor.
  3. 6+2-pin PCIe – for the video card.
  4. SATA – for SSD, HDD, and optical drives.
  5. Molex (4-pin) – for older devices and fans in a case you use them.

What internal components should reliable power supplies have?

Reliable power supplies have the following components at their heart:

  1. high-quality capacitors (often Japanese), 
  2. stable transformers and chokes, 
  3. an efficient voltage conversion circuit (DC-DC or Active PFC), 
  4. protection against overload, short circuit, and overheating, 
  5. high-quality cooling fans.

Modular vs. non-modular PC power supply designs

Modular PC power supplies are a solid standard among others, which PC users prefer most today. At the core of its construction – a fully modular design that allows you to connect only those cables that you need, according to your PC specifications and tasks it runs. It gives you full freedom in updating your PC build and using custom cables for premium builds as well.

Non-modular PC power supplies are the classic format, where all the cables are soldered to the power supply unit and cannot be disconnected. This PSU variant is typically the go-to option for budget builds that require power around 600-650W or below.

What types of protection should a power supply provide?

The complete set of built-in protection systems should include:

  1. Over-Current Protection – protection against overload at the current level on each power line.
  2. Over- and Under-Voltage Protection – automatic shutdown when the voltage rises or falls beyond acceptable limits.
  3. Over‑Power and Over‑Load Protection – protection against cases where the system requires more power than the PSU can provide.
  4. Over‑Temperature Protection – shuts down in case of overheating to prevent damage.
  5. Short‑Circuit Protection – the full shutdown in case of a short circuit.

How important are power supply brand, warranty, and reliability?

Well-known manufacturers use high-quality capacitors and other components that ensure the durability and efficiency of the power supply unit. It makes a lot of sense and gives you quality assurance. Why does a guarantee matter? A long warranty shows the brand trusts its product and is confident in its reliability and long-term performance. Some even cover PC parts replacement if the PSU causes damage. So, to make sure you get the best power supply for your PC, choose well-known brands with long warranties. Thus, unforeseen issues will be avoided, and the system will operate safely under any circumstances. 

Conclusion

Today, to choose the best power supply for your PC, you need to consider a bunch of factors that affect the final choice. Take into account the power requirements of all components and add an extra percentage for energy consumption. This is the best formula for determining the power of your power supply unit, which will serve you longer and ensure high performance for your PC. Whatever demanding task you work on.