How many Watts does your computer need?

The power supply is the "heart" of your computer: it provides power to all the components. The most common question is how many Watts (W) you should choose.

• Office / Basic Use Computers (350W – 500W): If the computer is intended for browsing, movies, and office work (without a separate, power-hungry graphics card), a quality power supply in this range is more than enough.

• Mid-range Gaming / Professional Systems (650W – 750W): The ideal range for most modern PCs with a good graphics card. It comfortably covers your needs and leaves room for future upgrades.

• High-End Gaming / Heavy Use (850W – 1000W+): Essential if you are building a top-tier system with the most powerful processors and the best graphics cards on the market.

? Super Tip: Don’t buy just enough Watts! Modern components often have sudden "spikes" in power demand. A power supply with some extra Watts ensures your PC will never suddenly shut down while you’re gaming or working.

Efficiency Certifications: 80 Plus and Cybenetics

You have surely seen labels like 80 Plus Bronze, Gold, or Platinum. These certifications indicate the energy efficiency of the power supply.

• The higher the rating (e.g., Gold instead of basic White), the less power is wasted as heat, which means lower electricity bills and cooler operation.

• Note, however: Efficiency does not equate to build quality!

Nowadays, many modern power supplies also carry certifications from the Cybenetics organization (with labels such as ETA for efficiency and LAMBDA for how quiet the fan is), which result from much stricter and more detailed testing.

How does it regulate energy efficiency?

A power supply, in order to produce 500 Watts at full power with an efficiency of 50%, will require 1000 Watts, meaning double the amount. The remaining 500 Watts will be released as heat into the environment. If a power supply has an efficiency of 80%, then to provide 500 Watts, it will need to consume 625 Watts. Note: both power supplies will deliver the power you need, but the first one will consume more energy! 

We can see, therefore, how important the efficiency of a power supply is, since a power supply with higher efficiency will have lower power consumption and will help cool the computer case as it will release less heat. 
In the table below, we see that a power supply certified with 80 Plus Silver means that at 100% load it has an efficiency of 87%. At 50% load it has 90%, and at 20% load it has 87%. This certification, therefore, tests a power supply at three different loads. The exception is the Titanium category, which also measures at 10% load.

Cables: Modular, Semi-Modular or Non-Modular?

The way the cables come out of the power supply determines how easy assembly will be and how tidy the inside of your case will look.

• Non-Modular (All cables attached): All cables are permanently connected. It is the most economical option, but the cables you don't use will need to be hidden inside the case.

• Semi-Modular: The basic cables (such as the motherboard power) are permanent, while the rest (for drives, graphics cards) you only connect if you need them. An excellent middle-ground solution.

• Full Modular (Fully detachable): No cable is permanent. You only connect exactly what you need. It offers the cleanest result, perfect airflow inside the case, and super easy installation.

Connections

Make sure that the power supply has all the necessary ports for your components. Most modern power supplies will have the required ports for a typical desktop computer.

Below is a brief summary of the cables most commonly found in power supplies:

• ATX 24-pin cables: These cables provide the main power to the motherboard.

• EPS 4+4-pin cables: These cables provide additional power to the motherboard, especially for high-performance processors.

• SATA cables: These cables provide power to storage devices and optical drives and are usually the ones you should check if they are enough for all your devices.

• Molex cables: These cables provide power to IDE drives, accessories, and even system fans. However, their use has decreased since the arrival of SATA.

• PCIe 6-pin cables: These cables provide power to graphics cards.

• PCIe 8-pin cables: These cables provide power to high-end graphics cards (6+2 pin connector).

ATX 3.0 / 3.1 and PCIe 5.0: What You Need to Know About the New Graphics Cards

If you plan to install a modern high-performance graphics card (such as the latest NVIDIA generations) in your computer, look for a power supply that supports the ATX 3.0 or ATX 3.1 standard.

These power supplies feature a new, dedicated cable called 12VHPWR (or 12V-2x6). With this single cable, you can power your graphics card directly and safely, avoiding the use of inconvenient adapters and multiple cables that create clutter. Additionally, they are designed to withstand the sudden power fluctuations of the new cards.