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How to choose PC power supply?

The power supply is one of the least fascinating but most crucial parts of a computer. Of course, energy is needed to power a PC, but not all of its internal parts receive power straight from the wall. Instead, electricity travels from the power company’s alternating current (AC) into the needed voltage of direct current (DC), which is used by PC components.

It can be tempting to purchase any power source to power your PC, but that is a bad idea. Instability that can be difficult to pinpoint is one of the many issues that can result from a power source that does not deliver dependable or clean electricity. In fact, a failing power supply frequently results in other issues like erratic resets and freezes that could otherwise go unnoticed.

Anticipate upgrades when buying a power supply

You see what I mean. Don’t just establish plans to fulfill your needs right now; also consider modifications you might wish to make in the future. Additionally, if you’re purchasing a pre-built PC, be careful to research the power supply it utilizes to ensure that it will support any future additions you might make or that it will be simple to swap out in the future.

A crucial point about power: continuous power and peak power are two entirely different things. The “Maximum Power” figure of a power supply often refers to the steady (continuous) power the PSU will produce, but the “Peak Power” figure denotes the heightened maximum (surge) power the PSU can deliver, albeit for a relatively little period of time (e.g., 15 seconds). Make sure the power supply you purchase has the constant wattage you require; otherwise, you can experience issues while your PC is under a heavy load.

Finally, don’t worry that purchasing a higher-rated power supply will result in you using more energy. Even while buying a larger power supply than you need can be a waste of money in the beginning, you won’t pay more to run your PC as a result of it. A power supply simply pulls the electricity required by your PC’s components.

Efficiency matters with a PSU

Wattage is only one metric used to assess a power supply’s efficiency. Another is its efficiency rating, which is a calculation of the amount of DC power it delivers to the PC and the amount that is largely lost as heat. Efficiency is crucial because it determines how much you’ll spend on maintaining your PC.

Think about a PC, for instance, which consumes 300 watts of power. Your PC will draw roughly 353 watts of input power from your power provider if you utilize a power supply with an efficiency rating of 85%. On the other hand, a power supply that is just 70% efficient will draw 428 watts from the wall. Your monthly power payment will decrease if you use the more economical power supplier.

A power supply with a greater efficiency rating will also enable your PC to operate at a cooler temperature. Every PC component produces some heat, which generally hinders peak performance. A less heat-dissipating power source will result in a quieter system because the fans won’t need to operate as quickly or as long, improved dependability, and a longer lifespan.

Will your power supply Form factor?

The next element to take into account is a straightforward one: You must choose a form factor that you are confident will physically fit inside your case. Fortunately, just like with enclosures and motherboards, there are standards for power supply. Although this subject might become rather complex, it’s crucial to keep in mind that your power supply should match your case and motherboard. The most significant power supply form factors available today are briefly described in the section below.

Even while AT form factor power supplies can still be purchased, they are unquestionably outdated items that are in decline. Even the earlier ATX 2.03 and later form factor power supplies are becoming less popular. The following are the main variations between the ATX and AT power supply form factors:

An additional +3.3V voltage rail is offered by ATX power supplies.
The main power connector for ATX power supplies is a solitary 20-pin connector.
The soft-off feature, supported by ATX power supplies, enables software to shut down the power supply.


If a power supply can’t connect to and power every part of your computer, it is useless. That implies that it must have each necessary sort of connector. The main connector that powers the motherboard should be taken into account first. There are two varieties of this connector: 20-pin and 24-pin. The latter is become more and more popular, and your power supply probably offers both. Just make sure by checking.

The CPU power connector, which is available in 4-pin and 8-pin models, comes next. Many contemporary motherboards have shifted to the bigger format, just like the main power connector. Once more, confirm that your power supply is compatible.

The 4-pin Molex connector is the most often used power connector. It’s utilized for several different parts, including vintage HDDs, optical drives, fans, and a few other things. In case you run out of either, Molex to SATA adapters can be used instead. Newer SATA components have their own SATA power connector. Additionally, splitter cables can be used to enhance the number of components you can connect; however, you should be aware of the maximum capacities of your power supply.

Fan noise and cable convenience

Now that we’ve thought about the most crucial power-related criteria, there are a few other factors to take into account when selecting a power source. These factors are less important, but they can impact how comfortable a power supply is to use for the duration of your PC’s life.

As we’ve already mentioned, heat is produced by power supply. Fans are therefore necessary for them to operate well and keep cool. You should think about how quiet you want your PC to run because this will be much influenced by your surroundings. Larger fans that spin more slowly to move the same quantity of air will probably make your PC quieter if it operates in a calm environment.

You will need to contrast the marketing materials for your power supply possibilities because there aren’t any clear standards for power supply cooling. In-depth reviews will be especially beneficial in this situation because they frequently measure a power supply’s noise output at various operating speeds and so provide some insight into the operating noise level of your PC.