How to choose a power supply for a PC

The durability of the components directly depends on the power supply. If you power them from a cheap and low-quality PSU, which is not even able to provide stable voltage on the 12V line, the components will quickly break. Their repair will either be impossible or expensive. Therefore, it is better to immediately buy a high-quality PSU.

To choose a good power supply, you don't need to be an expert in electronics. There are several signs that distinguish good power supplies from bad ones. Below we will talk about these signs in detail and tell you what parameters you need to look at to choose a high-quality, reliable and durable power supply for your PC.

Bequiet Power Supply - Capacitors — Bequiet Power Supply – Capacitors

Japanese capacitors

In fact, Japanese capacitors do not guarantee that the power supply will be 100% excellent. There are still many other components that the manufacturer can make a mistake with. However, no one will make a bad power supply with expensive Japanese capacitors. If the manufacturer wants to earn as much as possible and make cheap consumer goods, he will put very budget Chinese capacitors in the power supply.

How to determine what capacitors are in the power supply:

Capacitors for power supplies are made by 3 Japanese companies:

Nichicon;
Rubycon;
Nippon Chemi-Con.

To determine what capacitors are in the PSU, read text reviews on the Internet. Many specialized sites talk in detail about power supplies. Reviewers completely disassemble them and always list what components are in the PSU, including the types of capacitors. All of them should be from Japanese manufacturers.

Bequiet Power Supply - 80 Plus Certified — Bequiet Power Supply – 80 Plus Certified

80 PLUS Certificate

The certificate indicates the efficiency of the power supply, i.e. the ratio of useful energy to the actual energy spent. The higher the certification level, the better the quality of the power supply.

Certificates are as follows:

80 PLUS Standard – efficiency not less than 80%;
80 PLUS Bronze – efficiency of at least 82% at full load;
80 PLUS Silver – efficiency of at least 85% at full load;
80 PLUS Gold – efficiency of at least 87% at full load;
80 PLUS Platinum – efficiency of at least 89% at full load;
80 PLUS Titanium – efficiency of at least 90% at full load.

We recommend choosing power supplies with 80 PLUS Gold certification and higher. In theory, this does not guarantee that the PSU will be 100% excellent, but in reality, it is simply impossible to achieve 80 PLUS Gold and higher with poor circuitry and low-quality components.

If your budget is very limited, you can consider a PSU with an 80 PLUS Bronze certificate. Such a unit will no longer have expensive Japanese capacitors. Most likely, it will have Taiwanese capacitors, which is not bad for a budget PSU. The main thing is not to choose units with a lower certificate or without one at all. If the efficiency of the device is less than 82% at full load, it means that it has very cheap components that cannot ensure stable and long-term operation of computer components.

Availability of power factor corrector

This device is also called PFC, and it is simply a must-have in a modern computer power supply. The power factor corrector reduces energy loss by matching the phases of voltage and current at the input of the power supply. This improves the quality of power supply and allows the power supply to operate in wide ranges of input voltage.

There are two types of power correctors:

active – consists of a converter and a controller;
passive – consists of capacitive and inductive elements.

Modern power supplies should have active power correctors (active PFC or APFC). They are much better and more efficient than passive ones.

Power

Many people think that the more powerful the power supply unit, the better quality it is, but in reality this is not true. The performance of the power supply unit does not affect the reliability, durability and quality of the component base. It is very easy to make a powerful power supply unit from bad elements, and manufacturers often produce such models.

The power of the power supply simply indicates how much energy the device can produce. It has nothing to do with the quality of the component base.

The power of the power supply unit should be slightly higher than the power consumed by your components. Next, we will talk about how to find out the required performance of the power supply unit.

How to find out the required power supply capacity

To figure out the required power supply wattage, get out a calculator and calculate how many watts of power your components consume.

With video cards, everything is simple. Their power consumption is indicated directly in the specifications. With central processors, it is a little more complicated. Although their power consumption is indicated in the parameters, in reality it is not entirely true.

Therefore, it is better to look at text and video reviews to see how much power the processors actually consume.

For example, the 8-core AMD Ryzen 7 5700X specifications state 65 watts, but in the AIDA64 stress test, this CPU consumes 78 watts. It's the same story with Intel processors. For example, the Intel Core i5-13600K specifications state 125 watts, but in the AIDA64 stress test, the consumption is 181 watts.

All other computer components consume little power:

cooler up to 6 W;
hard drive up to 10 W;
SSD drive up to 3 W;
RAM module up to 6 W.

Just add their power to the CPU and GPU consumption and you will get the required power for the power supply.

Also keep in mind that you can find various online PC power consumption calculators on the Internet. We do not recommend using them, as they can be deceitful and add an additional 50-100 watts to the actual consumption of components. Such calculators only provide an approximate estimate of power consumption, not an exact one.

Is it necessary to select the power supply unit capacity “on the edge”

If your computer consumes, say, 300 watts of power at peak load, this does not mean that you need to choose a power supply with exactly the same power. Take a device with a small reserve – about 100-200 watts more.

This way, the component base of the power supply unit will not be loaded to the maximum, which will extend its service life. In addition, in the future, you will not have to change the power supply unit if you want to upgrade your PC and install a more powerful processor or video card.

Form factor

To make it easier for buyers to select power supplies for PCs, manufacturers have standardized their sizes and called them form factors.

The most common power supply form factors are:

ATX. Height – 86 mm, width – 150 mm;
SFX. Height – 63.5 mm, width – 125 mm;
TFX. Height – 64 mm, width – 85 mm.

The length of power supplies is not standardized and may differ even within the same form factor. Therefore, when choosing a unit, find out what maximum PSU length your case supports, and add another 5-10 cm to this to accommodate cables. This characteristic is easy to find in the case parameters. Just enter the case name on the Internet and go to the official website of the manufacturer or any store. The maximum supported PSU length is always indicated in the specifications.

Connectors and cables

The set of connectors on all power supplies is the same, but still check for the presence of:

20+4 pin – motherboard power supply;
4+4 pin – processor power supply;
6+2 pin – video card power supply;
12VHPWR – power supply for new NVIDIA video cards;
Molex – power supply for old storage devices, coolers and optical drives;
SATA – power supply for hard drives, optical drives, RGB and PWM controllers.

Always pay attention to the number of cables in the package. For example, many modern motherboards use a 16-pin processor power connector. That is, you will need two 4+4 pin cables. Make sure that the package includes a second cable.

Also, do not forget that new NVIDIA video cards always come with adapters from 6+2 pin to 12VHPWR. That is, the presence of a separate 12VHPWR cable in the power supply package is not necessary.

Detachable cables

According to the type of cables, power supplies are:

non-modular – it is impossible to disconnect cables;
modular – all cables can be disconnected;
semi-modular – the power cables for the processor, video card and motherboard cannot be disconnected.

If your budget allows, choose modular power supplies. You can't even imagine how much easier they make assembling a computer. It's very convenient to first insert cables into the components and only then connect them to the power supply. By choosing a modular PSU, you will save a lot of time and effort.

Cooling

Power supply components can become very hot during operation. To cool them, regular fans are used, which are installed at the bottom. They take in cool air and direct it directly to the hot elements of the power supply.

The fans can operate in two modes:

continuously – the cooler rotates at the same speed all the time;
adaptive – the cooler changes its rotation speed depending on the power supply temperature.

Power supplies with adaptive fans are a little more expensive than continuous fans, but they produce much less noise. They also have an extended service life, since they can rotate at a lower speed. Therefore, we recommend buying them.

If your budget is not limited, you can safely choose power supplies with passive cooling. The design of such devices does not include fans at all, which is why they are silent, and only metal radiators are responsible for cooling the components.