How to choose the right power supply for your computer

Buying a computer and assembling it is accompanied by the need to correctly select a sufficiently large number of components.

Moreover, in most cases, the buyer starts with a video card, processor, chooses a suitable motherboard. Alas, sometimes even the optical drive gets more attention than the power supply. But this is a fundamental component, without which nothing will work.

How to choose the best power supply for your computer

The task of the power supply unit (PSU) is to supply voltage to all consumers. Due to this, they work stably and correctly.

Contents

Power supply functions

In short, the power supply has 2 main functions. Namely:

  • Performing a rectifying task. In the household network, that is, in a regular outlet, alternating current flows. But for the components of the computer to work, you need to use direct current. To make a permanent from a variable, an intermediate link is installed between the outlet and the PC filling in the form of a power supply unit.
  • Delivery of food to consumers with different needs. Various components of a PC consume a certain voltage to operate. And it is not the same everywhere. The power supply unit has 3 voltage lines. These are 3.3, 5 and 12 V. The most powerful consumers are connected to the 5 and 12 V lines. This is a video card, processor, etc.

Power supply circuitry

All this suggests that the existence of a PC without a power supply is impossible. And at the same time, the block acts as a very important component for any computer. His choice must be approached very carefully.

Criterias of choice

Now in more detail about how to choose the right power supply for your computer and what characteristics you will need to pay special attention to.

It makes no sense to consider the circuits in depth and study the theory in the field of electrical engineering. It is enough to find out only what is useful to the average user.

A competent buyer will naturally be interested in how to correctly calculate the power of a suitable power supply for a computer so that the latter can work stably and efficiently. Excess power is not needed. But too small an indicator will lead to a violation of stability. It is corny that the power supply unit will not be able to power all consumers, and there is no need to talk about the normal operation of the computer.

Calculating the power of the power supply using the utility

Thinking about how to choose a power supply that matches the characteristics of your computer, you need to focus on the following characteristics and parameters:

  • power;
  • Efficiency;
  • current strength;
  • form factor, dimensions and weight;
  • cooling system;
    Types of cooling systems for a computer
  • manufacturer;
    Popular power supply assembly companies
  • guarantees and so on.

Several additional parameters will be considered within the listed characteristics. They also deserve attention.

Power

When calculating a suitable power supply for the computer being assembled, the main emphasis is placed on its power. This is the main characteristic and is measured in watts (watts).

The correct choice of power supply for a PC is made based on a simple pattern. The power should not be lower than the value that the system will require at maximum load. The most active consumers are components such as the processor and graphics card. All other elements require much less power.

If you need to choose the correct and suitable power supply for your PC, then you need to add up the power consumption parameters of all components, and add another 20% to the resulting value for a margin. This reserve will come in handy at maximum loads. It is also useful if there are plans to replace some components with more powerful ones in the future.

To ensure that the power is sufficient in terms of power, take a look at the specifications of the processor and video card. You can also take into account the connectors on the video card, focusing on their limit values ​​for power transfer:

  • PCI-E 16x can transfer up to 75W;
  • for 6-pin this figure is also 75 W;
  • at the 6 + 2 pin video card connector, it reaches 150 W.

Table of connectors for additional power supply of computer components

In theory, if a video card has 2 connectors 6 and 6 + 2 pins, it can consume up to 300 watts.

Now a few more illustrative examples.

  • Motherboard. An important component of a computer, since it contains all the necessary upgrade. Power consumption depends on the number of power phases, additional modules, type of voltage regulator and chipset. The average power consumption for PC motherboards is 40-50 watts. But for top models, when a power supply is selected for a gaming computer, the motherboard can require about 80 watts. And then it is better to choose a more powerful PSU.
  • Optical drive. Now this is not the most demanded component. But it is better to take it into account too. The optical drive can consume a maximum of 30 watts.
  • Data storage devices. They are also hard drives (HDD) or solid state drives (SSD). Their energy consumption figures are quite low. An SSD has no more than 3 W per disk, while an HDD has about 8-10 W.
  • Cooling system. For some reason, little attention is paid to the power consumption of this component in PCs. This is not entirely correct, since it is recommended to allocate 15-20 watts in advance for the cooling system. And this can significantly affect the final choice.
  • RAM. It consumes practically nothing. The weakest energy consumer. But still, it is better to lay 5 watts of power on each of the slats.

In order not to study the power consumption parameter of each individual computer component and not bother with calculations, you can use special online calculators. They are available directly on the websites of the power supply manufacturer.

To draw intermediate conclusions, it is worth starting from the following recommendations:

  • From 300 to 400-450 watts. This power supply unit is enough to operate an office computer, PCs with integrated or frankly weak video cards.
    Low Power Consumption Office Computer
  • 450-600 watts. Suitable for high-performance PCs, as well as entry-level gaming computers with 1 graphics card. But when overclocked, this power may no longer be enough.
  • 600-750 watts. Optimal for a gaming PC with 1 video card, when you also need a good headroom for overclocking.
  • 750 W and above. The most powerful PCs with 2 video cards used for server building, mining, etc.
    Powerful computer with 6 video cards for mining

For some users, these values ​​will already be enough to navigate the offered assortment and make the right choice. But there is no need to rush.

Efficiency

This may seem strange to some, but if you do not know how to choose a suitable power supply for a PC, then it will definitely not be superfluous to pay attention to such a characteristic as efficiency.

Even if the power supply unit has high power, this does not mean high-quality work and exemplary efficiency. Efficiency is largely reflected in such a parameter as efficiency.

The efficiency of a PSU demonstrates how much of the mains power is transferred to the system. The higher the efficiency, the less the unit heats up, and the energy is spent more efficiently. Since there is no strong heating, the computer operates in the optimal temperature mode, it functions quietly due to the absence of the need to forcibly spin the fans more strongly.

The 80 Plus standard is used to assess the efficiency. It has several levels of efficiency. From best to worst, this rating looks like this:

  • Titanium
  • Platinum
  • Gold
  • Silver
  • Bronze
  • White / Standart

80 PLUS standard: table of efficiency values ​​at different loads

An obvious pattern is at work here. The higher the level, the higher the cost will be. But it is justified by the lower power consumption of the computer. And this is the need to pay less for electricity in the house. Plus, the load on the computer is reduced, the cooling systems are less loaded. That is, it really makes sense to overpay for a power supply unit with a higher level of efficiency.

Amperage and lines

The total power of the computer power supply is formed based on the power indicators that the power supply unit is capable of providing for individual lines. If you exceed the maximum load on one of the power lines, the device will no longer work stably. This is possible even if the power consumption is significantly different from the nominal, and there is a margin.

It has already been said that the power supply unit has 3 lines of force.

  • 3.3V. It is fed to the RAM, and also powers the motherboard itself.
  • 5B. This amount of Volts goes to the motherboard, is fed to the drives, and also goes to the optical drives.
  • 12V. The main sources of consumption from this line are the processor and video card. It is this line that the unit must provide with the greatest power.

Power supply lines

Relevant information about the characteristics of the power lines can be found in their data sheet of the unit, or in the documentation attached to it.

Correction module

Don’t forget about the Power Factor Correction (PFC) module, which is able to increase the efficiency of the PSU. This is a special component that edits the power factor and focuses on protecting the network.

Modules are passive and active. Active is designed to equalize the input voltage. With its help, all devices work more stable. This type of module is objectively better. But that is why it is more expensive.

PFC tag on power supply

Dimensions, weight and form factor

Currently, the ATX standard is used for the mass consumer segment. It provides compatibility with all standard ATX computer cases. Plus, they fully correspond to the characteristics of ATX motherboards.

Dimensions and form factors of computer cases

If we talk about PC users and buyers in the post-Soviet space, then here you basically need to focus on the designation ATX 12V 2x. The standard block has dimensions of 150×86 mm. But the length of the model may differ from each other.

When the space for installing components is limited, and a compact PC case is used, then you should pay attention to the SFX-L or SFX form factor. They fully comply with ATX 12V2x standards, but at the same time have a small size.

As for the weight, then the weight here largely reflects the quality of the components used. And the more weight is, the more effective the device will be. Although the mass should not be attributed to the fundamental characteristics.

ADVICE. It is not recommended to buy power supplies that are downright light. This indicates their maximum budget.

Hence the corresponding quality, low efficiency, questionable efficiency. Plus, such power supplies may not correspond to the declared characteristics at all.

Power supplies and cable connections

Power supplies are divided into 3 categories depending on how the unit is connected to the cables:

  • Non-modular. It is a non-modular design. All cables are pre-installed and cannot be disconnected. If not all connectors are used, a mess will form in the system unit.
  • Semi-modular. Partially modular devices. Here, only the main cables remain non-removable. All others can be turned off as needed.
  • Full-modular. Fully modular housing. Each cable is disconnected. Very convenient and practical. But it is also the most expensive type.

Modular design of the power supply

This is not to say that this seriously affects performance or productivity. But in terms of the convenience and neatness of the system unit, it is better to choose partially or completely modular designs.

Connectors

Also, be sure to look at what connectors the purchased power supply is equipped with. Not all of them will allow you to connect accessories that go beyond the standard set.

  • Main cable for the motherboard. This is a 20 + 4 pin connector.
    Main motherboard cable for 20 + 4 pin connector
  • Processor power cable. Most often it is 4 pin. But you can also find 8 pin and 4 + 4 pin, which are used for processors with increased power.
    4 pin cable for CPU power supply
  • SATA hard drive connector.
    SATA hard drive cable
  • Power supply of peripheral devices. This applies to IDE hard drives and CD / DVD drives.
    Peripheral cables
  • PCI Express cable. Provides power to everything that connects to the bus. It can be a video card, a network card, etc. Mainly a 6 + 2 pin connector is used. But there are 6 and 8 pin.
    PCI Express cable

It is better to take into account the complete set of the system unit in advance, and provide for the possibility of connecting all equipment through the purchased power supply.

Manufacturers

It is important to understand that a number of large brands are not equipped with their own production. They order their assembly from other OEMs. Therefore, power supplies of different brands can in fact be produced by the same enterprise.

But at the same time, each brand values ​​its reputation. This forces us to carefully approach the issue of production, to control the build quality so that the end consumer is not disappointed with his choice.

There are several companies worth paying attention to:

  • Corsair
  • EVGA
  • ExeGate
  • AeroCool
  • Deepcool
  • Seasonic
  • Cooler master
  • Enermax
  • Chieftec
  • Silverstone
  • NZXT
  • Thermaltake

Choose the right one not by name, but by characteristics. First, focus on the main technical parameters and only then look at the brand. It is better not to take products of dubious firms and unknown manufacturers.

Guarantee

In addition to brand, performance and other parameters, it is worth taking a look at how long the warranty covers.

In fact, the warranty reflects the manufacturer’s confidence in the quality of their products. PSUs cannot be considered different materials, since they usually last as long as the computer itself. Sometimes they are rearranged to new PCs, where the unit continues to work stably.

The cheapest PSUs are usually offered with a 2-3 year warranty. Yes, for certain components this is already a lot. But not in the case of the power supply. Leading manufacturers provide a 5-10 year warranty. And they do an excellent job with such a long-term operation.

Marketing gimmicks

A few more words about how buyers are trying to lure, deceive or mislead.

There are a number of marketing tricks that make a product more attractive than it actually is. Consider popular examples:

  • Using Japanese capacitors. It’s good. But only on condition that they did not save on the other components. Capacitors alone cannot seriously affect the quality.
  • Application of all types of protection. By default, all power supplies must have overvoltage and overload protection. It’s just that it’s implemented differently for everyone.
  • Active PFC. Now this is already a gimmick, since more than 95% of modern PSUs have abandoned passive PFCs.
  • Use of DC-DC converters. This indicates a rejection of the old group stabilization. Again, most PSUs no longer use this circuit. And even on budget models. Converters are almost everywhere.
    DC-DC converter

So it turns out that behind the beautiful inscriptions are quite obvious characteristics.

Summarizing

Only the buyer himself can decide which power supply is best suited for his computer, and therefore he must choose based on the requirements and financial capabilities.

Don’t underestimate the importance of BP. But to a greater extent, this applies to powerful gaming computers.

For ordinary PCs for office use, for simple games and working on the Internet, it is enough to buy an average block in all respects. And it will be enough to meet all your needs. Chasing the most expensive and efficient power supplies is a must when buying the right powerful and high-end PC components.

What PSU are you using? Why did you prefer this particular model / manufacturer? What blocks do you advise against taking and for what reason?

We are waiting for your answers in the comments.

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