PSUs: specifications, types

The output power of the power supply, in other words, is the maximum power that it is capable of delivering to the system. For the computer to operate efficiently, the power supply must be greater than the total power consumption of the system at maximum load. The latter can be calculated by summing the power of individual components, however, in general, for office configurations , about 400 W — 450 W is considered sufficient, for medium gaming — about 600 W( 500 W, 550 W, 650 W, 700 W, 750 W), and for the top ones — power of 800 W and above ( 850 W, 1000 W and even more than 1 kW).

The form factor determines, first of all, the dimensions, and, as a result, the purpose of the power supply. To date, there are such main form factors:

— ATX. Conventionally, it can be called "standard" — this is the most common form factor for regular-sized desktop PCs (in Full Tower and Midi Tower cases).

— TFX. Compact form factor, designed specifically for small cases (in particular, Mini Tower). Due to their intended use, these power supplies are typically lower than full-sized ATX power supplies, while electrically they are fully ATX compliant.

— SFX. Modification of the ATX form factor, developed at the end of the 20th century as a power supply option for systems in miniature microATX and FlexATX form factors (the S in the name stands for "small", i.e. "small"). Accordingly, the main difference is the dimensions: they are much smaller and amount to (width-depth-height) 100x125x64 mm with a standard 60 mm fan. When installing larger or smaller fans, the height of the unit changes accordingly; there are other deviations from the standard (for example, a slightly greater depth). The power connectors are almost identical to the original ATX, and these two standards are considered completely interchangeable.

The type of power factor correction (PFC) provided in the power supply.

The power consumed by the PSU is divided into active and reactive; the first goes to perform useful work, the second does not produce such work and is dissipated in the form of heat. The power factor is the ratio of active power to the total power consumed; the closer it is to one, the more efficient the PSU.

PFC correction is applied to improve the power factor. It can be done passively or actively. The first option provides the presence of a coil (choke), which partly compensates for the operation of the reactive components of the PSU; such a correction is simple and inexpensive to implement, but not very effective. The active method, in turn, provides the presence of a specialized controller. It is more expensive, but the power factor in such PSUs can reach 0.95 or more; in addition, the device is more resistant to voltage drops.

In general, for use in a home or small office, passive correction is more than enough; active PSUs should be specifically looked for mainly in cases where we are talking about numerous computers connected to a powerful UPS.

Efficiency, in this case — the ratio of the power of the power supply (see "Power") to its power consumption. The higher the efficiency, the more efficient the power supply, the less energy it consumes from the network at the same output power, and the cheaper it is to operate. Efficiency may differ depending on the load; the characteristics can indicate both the minimum efficiency and its value at an average load (50%).

It should be noted that compliance with one or another level of 80PLUS efficiency directly depends on this indicator (for more details, see "Certificate").

— 1 fan. The most common option. The power of such a system is quite enough to cool the power supplies, including Above average and relatively inexpensive. On the other hand, fan operation creates noticeable noise, especially in low-cost power supplies with small diameter fans (see "Fan Diameter").

— 2 fans. The second fan is usually installed in powerful power supplies, for which the power of one fan is not enough. The price for such efficiency, in addition to increased cost, is an increased noise level.

— to Semi-passive cooling. A function that allows you automatically turn off the PSU cooling system in situations where the load on the power supply is low and heat dissipation is reduced. It is found only in models with active cooling. Recall that systems of this type are more efficient than passive ones, but they consume additional energy and create noise during operation. Accordingly, at a light load, when intensive cooling is not required, it is more reasonable to turn off the fans — this saves energy and reduces the noise level.

— Passive(radiators). Compared to fans, heatsinks have a number of advantages: for example, they do not create noise at all and do not require their own power supply (thus reducing overall power consumption). On the other hand, they are much less efficient, as a result — the power...of power supplies with passive cooling does not exceed 600 watts. In addition, these PSUs are quite expensive.

The diameter of the fan(s) in the power supply cooling system.

The large diameter allows to achieve good efficiency at relatively low RPMs, which in turn reduces noise and power consumption. On the other hand, large fans are more expensive than small ones and take up a lot of space, which affects the dimensions of the entire PSU. We also emphasize that a small fan is not yet a sign of a cheap power supply — quite advanced models can also have such equipment, in order to reduce dimensions.

As for specific diameters, the smallest value that can be found in modern consumer-grade PSUs is 80 mm. The most popular option is 120 mm, this size gives good efficiency and a relatively low noise level at a reasonable price and dimensions. Larger diameters are somewhat less common — 135 mm and 140 mm.

The bearing is the piece between the rotating axle of the fan and the fixed base that supports the axle and reduces friction. The following types of bearings are found in modern fans:

— Sliding. The action of these bearings is based on direct contact between two solid surfaces, carefully polished to reduce friction. Such devices are simple, reliable and durable, but their efficiency is quite low — rolling, and even more so the hydrodynamic and magnetic principle of operation, provide much less friction.

— Rolling. They are also called "ball bearings", since the "mediators" between the axis of rotation and the fixed base are balls (less often — cylindrical rollers) fixed in a special ring. When the axis rotates, such balls roll between it and the base, due to which the friction force is very low — noticeably lower than in plain bearings. On the other hand, the design turns out to be more expensive and complex, and in terms of reliability it is somewhat inferior to both the same plain bearings and more advanced hydrodynamic devices. Therefore, although rolling bearings are quite widespread nowadays, however, in general, they are much less common than the mentioned varieties.

— Hydrodynamic. Bearings of this type are filled with a special liquid; when rotated, it creates a layer on which the moving part of the bearing slides. In this way, direct contact between hard surfaces is avoided and friction is significantly reduced compared to previous...types. Also, these bearings are quiet and very reliable. Of their shortcomings, a relatively high cost can be noted, but in fact this moment often turns out to be invisible against the background of the price of the entire system. Therefore, this option is extremely popular nowadays, it can be found in cooling systems of all levels — from low-cost to advanced.

— Magnetic centering. Bearings based on the principle of magnetic levitation: the rotating axis is "suspended" in a magnetic field. Thus, it is possible (as in hydrodynamic ones) to avoid contact between solid surfaces and further reduce friction. Considered the most advanced type of bearings, they are reliable and quiet, but expensive.

The presence or absence of an 80+ certificate for the power supply. This certificate indicates high energy efficiency: to obtain it, the efficiency (see above) must be at least 80%, and in different modes (20%, 50% and 100% of the maximum load). There are several degrees of 80+:

— 80+. The original version of the certificate, assuming an efficiency of at least 82% (at least 85% for 50% load).

— 80+ White. The second name of the original 80+ certificate (see above).

— 80+ Bronze — efficiency not less than 85% (for half load — 88%).

— 80+ Silver — respectively 87% (90% for half load).

— 80+ Gold — 89% (92% for half load)

— 80+ Platinum — 90% (94% for half load).

— 80+ Titanium — 94% (96% for half load).

The power factor (see "PFC Type") must be at least 0.9 for the lower levels and at least 0.95 for the Platinum level. Also note that for redundant power used in server systems, the efficiency requirements are somewhat lower.

A standard for power supplies that supplements the ATX specifications regarding power supply along the 12 V line. Introduced into use since the time of the Intel Pentium 4 processor. In the first series of the standard, the +5 V line was mainly used; from version 2.0, the +12 V line was introduced to fully power the components computer. Also in the second generation, a 24-pin power connector appeared, used in most modern motherboards.

The version of the EPS12V standard that the power supply complies with. The EPS12V standard was created primarily for high consumption PCs (with a power of more than 700 W, see "Power") and entry-level servers. Such power supplies have a 24-pin plug for the motherboard and an 8-pin processor power connector (sometimes more than one, see “MB / CPU Power” for more details). They are also more reliable than ATX12V. They are compatible with most ATX standard motherboards, however, in older motherboards, there may be problems with matching connectors, so this issue should be clarified separately (however, to solve this problem, in some power supplies, parts of the plugs are made removable, which allows them to be reduced if necessary to the dimensions of the connectors on the motherboard).

The number and type of connectors provided in the PSU to power the motherboard or processor.

This parameter is written as the sum of several numbers, for example, "24+4". The first number in such an entry means the number of contacts in the connector for powering the motherboard; in the vast majority of cases, this is just 24, since modern motherboards use a 24-pin connector as standard. The second number describes the socket for powering the processor; most entry-level and mid-range CPUs use 4-pin power, but powerful chips may require 8-pin power. There can be several 4- or 8-pin connectors — based on powerful high consumption processors.

A separate case is the blocks of the "24 (20 + 4)" format. They have two separate plugs — 20 pin and 4 pin, which allows you to power both 24-pin motherboards and older 20-pin motherboards from such power supplies. At the same time, such models do not provide a separate power supply for CPU — it is powered only through the socket, and the 4-pin plug cannot be connected to any other components except the motherboard.

Now on the market there are PSUs with such power supply for the motherboard: 24 pin (20+4), 24+4 pin, 24+8(4+4) pin, 24+8+8(4+4) pin.

The number of SATA power connectors provided in the PSU.

Nowadays, SATA is the standard interface for connecting internal hard drives, and it is also found in other types of drives (SSD, SSHD, etc.). Such an interface consists of a data connector connected to the motherboard, and a power connector connected to the PSU. Accordingly, in this paragraph we are talking about the number of SATA power plugs provided in the PSU. This number corresponds to the number of SATA drives that can be simultaneously powered from this model.

The number of Molex (IDE) connectors provided in the design of the power supply.

Initially, such a connector was intended to power peripherals for the IDE interface, primarily hard drives. And although the IDE itself is completely obsolete today and is not used in new components, however, the Molex power connector continues to be installed in power supplies, and almost without fail. Almost any modern PSU has at least 1 – 2 of these connectors, and in high-end models this number can be 7 or more. This situation is due to the fact that Molex IDE is a fairly universal standard, and with the help of the simplest adapters, components with a different power interface can be powered from it. For example, there are Molex - SATA adapters for drives, Molex - 6 pin for video cards, etc.

The number of 6-pin (6pin) PCI-E power connectors provided in the power supply.

Such connectors are used for additional power supply of those types of internal peripherals for which 75 W is no longer enough, supplied directly through the PCI-E socket on the motherboard (video cards are a typical example). The 6-pin connector on the power supply additionally provides another 75 W — thus, when using this connector, it becomes possible to connect boards with a power consumption of up to 150 W.

Note that some video cards have several connectors for additional power at once. Thus, the PSU can provide both one PCI-E 6pin plug, and two such connectors. However, in general, this type of plug is used quite rarely — this is due to the spread of a more convenient and versatile 8pin connector in the “6 + 2” format, which can be used both as six- and eight-pin (see below for more details).

The number of 8-pin (8pin) PCI-E power connectors provided in the power supply. We emphasize that in this case we are talking about ordinary connectors of this type, working only in the 8pin format; the number of combined 8pin (6+2) plugs is specified separately (see below).

Additional PCI-E power connectors are used to additionally power those types of internal peripherals for which 75 W is no longer enough, supplied directly through the PCI-E socket on the motherboard (video cards are a typical example). The 8-pin connector on the power supply additionally provides another 150 W — thus, when using this connector, it becomes possible to connect boards with a power consumption of up to 225 W. At the same time, some power supplies can be equipped with several PCI-E power plugs at once — based on powerful video cards that have several external power connectors, or on several separate video cards. However, it is worth noting that the classic PCI-E 8pin is rare nowadays — the more convenient and versatile PCI-E 8pin (6 + 2) has become more widespread. See below for more details.

The number of PCI-E 8pin (6+2) power connectors provided in the PSU design.

Additional PCI-E power connectors (all formats) are used to additionally power those types of internal peripherals for which 75 W is no longer enough, supplied directly through the PCI-E socket on the motherboard (video cards are a typical example). In PC components, there are two types of such connectors — 6pin, providing up to 75 W of additional power, and 8pin, giving up to 150 W. And the 8pin (6 + 2) plugs used in power supplies are universal: they can work with both 6-pin and 8-pin connectors on the expansion board. Therefore, this type of plug is the most popular in modern PSUs.

As for the quantity, on the market you can find models for 1 PCI-E 8pin (6 + 2) connector, for 2 such connectors, for 4 connectors, and in some cases — for 6 or more. Several of these plugs can be useful, for example, when connecting several video cards — or for a powerful high-performance video adapter equipped with several PCI-E additional power connectors.

the 16-pin PCI-E power connector is designed to replace the existing 8-pin counterparts. It consists of twelve lines for current supply and four more for data transmission. The connector provides up to 600 W of additional power, which is a fourfold increase in power compared to 8-pin versions of the interface. Additional PCI-E connectors of all formats are used to power those types of internal peripherals that are no longer enough with 75 W supplied directly through the PCI-E socket on the motherboard.

The presence of at least one Floppy power connector in the PSU.

Initially, this connector was intended to power floppy disk drives, hence the name. It is also known under the designation "mini-Molex". Anyway, this standard is generally considered obsolete, but it is still used by some specific types of components, and therefore continues to be used in power supplies.

The cable system used in the power supply. According to this parameter, modular, semi- modular and non-modular devices are distinguished, here are their features:

— Not modular. The classic version of the design, used in computer power supplies from the very beginning and not losing popularity to this day. The wires in such systems have a non-detachable design, and additional cables are not provided for connection. As a result, the user has to deal with only those cables that the manufacturer provided, without the ability to remove or replace them (the only modifications available are the installation of additional accessories such as an extension cord or splitter). Because of this, such PSUs are less convenient than modular and semi-modular ones: their wires are often excessively long, and some of them are not used at all, while such an “economy” further clutters up the case, worsening air circulation and cooling efficiency. On the other hand, these shortcomings can be reduced to almost zero with careful selection of the PSU and careful wiring; and non-modular systems themselves are distinguished by reliability and at the same time low cost. It is because of these features that they are most common nowadays.

— Modular. Systems in which each cable is made detachable; special sockets are used for fastening wires. Thanks to this design, you can optimally organize the space inside the PC —...for example, remove unnecessary wires so that they do not interfere with air circulation in the system unit; replace a cable that is too long with a shorter wire (or vice versa); swap cables, etc. At the same time, modular systems are noticeably more expensive than non-modular ones, while they are considered somewhat less reliable due to the presence of "weak points" in the form of removable cable mounts.

— Semi-modular. A kind of compromise between the options described above: some of the wires in such power supplies are made non-removable, some are equipped with modular mounts. This makes it possible to partially combine the advantages and compensate for the disadvantages of the two systems: semi-modular PSUs are less expensive and more reliable than modular ones, and at the same time more convenient than non-modular ones. Usually, in systems of this type, the most important wires have a non-removable design, which are almost guaranteed to be used when assembling a PC, and secondary cables are equipped with removable mounts and can be removed if not needed. However, the specific features of a semi-modular PSU should be specified separately.

The presence of a braid in the complete wires of the system unit — for all or at least for some.

This feature has a positive effect on reliability, making the wire as resistant as possible to bending, abrasion, strong pressure and other similar influences; it also provides additional protection against accidental contact with sharp objects (for example, when repairing a PC). The disadvantages of braided wires, in addition to increased cost, are also increased thickness and greater rigidity than similar cables in conventional insulation. This can create some difficulties in organizing space inside the system unit.

The maximum values of current and power that the PSU can provide on individual power lines.

The power line can be simply described as a pair of contacts for connecting a particular load; one of these contacts is “ground” (with zero voltage), and the second has a certain voltage with a plus or minus sign, this voltage corresponds to the voltage of the power line. In this paragraph, it is + 3.3V (such power is present in 20- and 24-pin connectors for motherboards, in SATA power connectors and some other types of connectors).

In general, power and currents are rather specific parameters that the average user rarely needs — mainly when connecting high-power components such as video cards, as well as when starting a PSU without a computer to power other electronics (for example, amateur radio stations). It is also worth mentioning that the sum of the maximum powers on all lines can be higher than the total output power of the PSU — this means that all lines cannot operate at full power at the same time. Accordingly, when the PSU is fully loaded, some of them will produce less power than the maximum possible.

The maximum current that the PSU is capable of issuing + 5V to the power line. For more information about power lines in general, see "+3.3V". Also note here that + 5V power, in addition to connectors for motherboards (for 20 and 24 pins), is also found in Molex and SATA plugs, as well as some other specific types of connectors.

The maximum current that the PSU is capable of delivering to the first power line is + 12V.

For more information about power lines in general, see "+3.3V". Here it is worth mentioning that 12 V is the most popular voltage among computer power connectors. It is used in almost all such connectors (with a few exceptions), and some plugs (for example, additional PCI-E power for 6 or 8 connectors) use only 12-volt lines — and in the + 12V format. And the division of + 12V power into several separate lines is used for safety purposes — in order to reduce the current flowing through each individual wire, and thus prevent excessive load and overheating of the wiring. However, some manufacturers do not specify the maximum current for individual + 12V lines and give only a general value in the characteristics; in such cases, this number is indicated in this paragraph.

The maximum current that the PSU is capable of delivering to the second power line is + 12V.

For more information about power lines in general, see "+3.3V". Here it is worth mentioning that 12 V is the most popular voltage among computer power connectors. It is used in almost all such connectors (with a few exceptions), and some plugs (for example, additional PCI-E power for 6 or 8 connectors) use only 12-volt lines — and in the + 12V format. And the division of + 12V power into several separate lines is used for safety purposes — in order to reduce the current flowing through each individual wire, and thus prevent excessive load and overheating of the wiring. However, some manufacturers do not specify the maximum current for individual + 12V lines and give only a general value in the characteristics; in such cases, this number is indicated in the paragraph "+12V1".

The maximum current that the PSU is capable of delivering to the third power line is + 12V.

For more information about power lines in general, see "+3.3V". Here it is worth mentioning that 12 V is the most popular voltage among computer power connectors. It is used in almost all such connectors (with a few exceptions), and some plugs (for example, additional PCI-E power for 6 or 8 connectors) use only 12-volt lines — and in the + 12V format. And the division of + 12V power into several separate lines is used for safety purposes — in order to reduce the current flowing through each individual wire, and thus prevent excessive load and overheating of the wiring. However, some manufacturers do not specify the maximum current for individual + 12V lines and give only a general value in the characteristics; in such cases, this number is indicated in the item "+12V1".

The maximum current that the PSU is capable of delivering to the fourth power line is + 12V.

For more information about power lines in general, see "+3.3V". Here it is worth mentioning that 12 V is the most popular voltage among computer power connectors. It is used in almost all such connectors (with a few exceptions), and some plugs (for example, additional PCI-E power for 6 or 8 connectors) use only 12-volt lines — and in the + 12V format. And the division of + 12V power into several separate lines is used for safety purposes — in order to reduce the current flowing through each individual wire, and thus prevent excessive load and overheating of the wiring. However, some manufacturers do not specify the maximum current for individual + 12V lines and give only a general value in the characteristics; in such cases, this number is indicated in the paragraph "+12V1".

The maximum current that the PSU is capable of issuing to the power line is -12V.

For more information about power lines in general, see "+3.3V". Here it is worth mentioning that 12 V is the most popular voltage among computer power connectors. However, most often it is used in the + 12V format; and the -12V line performs mainly a service function, it is almost never found in other connectors, except for the motherboard power plug (for 20 or 24 pins).

The maximum current that the PSU is capable of issuing + 5Vsb to the power line.

For more information about power lines in general, see "+3.3V". Specifically, the + 5Vsb line is used to power the computer electronics in standby mode, when the main and only task of the system is to respond to pressing the power button. This does not require high power, so this figure rarely exceeds 3A.

The maximum power that the PSU is capable of delivering to the + 12V power line.

See "Maximum current and power" for details on power lines in general. Here it is worth mentioning that 12 V is the most popular voltage among computer power connectors. It is used in almost all such connectors (with a few exceptions), and some plugs (for example, additional PCI-E power for 6 or 8 connectors) use only 12-volt lines — and in the + 12V format. So this indicator is one of the most important characteristics of any PSU.

Note that many power supplies have several separate + 12V power lines. In such cases, the total power is indicated here, which, usually, is divided equally between the lines.

The maximum power that the PSU is capable of delivering on the + 3.3V and + 5V power lines.

See "Maximum current and power" for details on power lines in general. Here we note that the power lines + 3.3V and + 5V are used both in the general connector for the motherboard (for 20 or 24 pins), and in specialized plugs — in particular, the SATA power connector (both) and Molex (only +5V, in addition to +12V). The power of these lines is a rather specific parameter, rarely required in fact; it is usually the same for both voltages, so it is indicated in the general clause.

The maximum power that the PSU is capable of delivering to the power line is -12V.

See "Maximum current and power" for details on power lines in general. Here we note that -12V is a rather specific format used exclusively in power plugs for motherboards — to supply power to individual motherboard components that require reverse polarity.

The maximum power that the PSU is capable of delivering to the power line is + 5Vsb.

See "Maximum current and power" for details on power lines in general. Here we recall that the + 5Vsb line is used to power the computer electronics in standby mode, when the main and only task of the system is to respond to pressing the power button. This does not require high power, so this figure rarely exceeds 15 watts.

A security system that protects computer components from a critical increase in voltage at the PSU output. In such situations , overvoltage protection cuts off the power supply, preventing damage to PC components.

The presence of surge protection is almost mandatory for modern PSUs, since it is part of the generally accepted ATX12V power supply standard. On the other hand, note that a specific OVP threshold can be quite high (inexpensive PSUs are especially susceptible to this), which is why such protection is sometimes useless in fact. So for maximum guarantee, it is highly desirable that OVP be supplemented with other security systems.

A security system that turns off the power supply when critical values of the output current are exceeded. This avoids overloading and failure of computer components. The difference between such a system and SCP (short circuit protection) is that overcurrent protection operates at a relatively low current and high resistance — that is, in a situation that is not yet a short circuit, but can damage computer parts. In addition, OPP takes into account the total current (total power) on all power channels and can work even if the current on each individual channel is within acceptable limits, but the total indicator is already above the critical value.

A system that protects the power supply (and in some cases, system components) from short circuits.

Recall that a short circuit is a situation when the resistance at the PSU output drops to zero — for example, with direct contact of the wire of one of the power lines with the ground wire. In such situations, the current rises to very high values and the PSU is subjected to significant loads that are fraught with damage. Short-circuit protection prevents these consequences by turning off the power when the output current rises sharply.

Separately, it is worth noting that this system should not be confused with OPP — overcurrent protection (see above): OPP operates at much lower currents than SCP, so these are two separate functions.

Protection circuits provided in the power supply. In addition to the OVP (overvoltage protection), OPP (overcurrent/power protection), and SCP (short circuit protection) described above, modern PSUs may include the following safety features:

— O.C.P. Overload protection on individual power outputs. It differs from OPP in that it takes into account not the total current consumption, but the current at each output separately.

— UVP. Undervoltage protection at the output of the power supply. For some components, such a voltage is as undesirable as an increased voltage: for example, a hard drive at reduced power cannot spin the plates to the required speeds. Usually, UVP is activated when the voltage drops by 20 – 25%.

— OTP. Protection against overheating of individual components of the power supply.

— SIP. Protection against voltage surges and surges is, in fact, a built-in stabilizer that can smooth out these surges to a certain extent. This feature does not eliminate the need for an external stabilizer, but it improves the overall performance of the protection.

— A.F.C. Not so much a protective as an “energy saving” function: automatic fan speed control, which allows you to change the speed depending on the load and the actual heat dissipation of the PSU. In addition to saving energy, this adjustment also reduces wear on the moving parts of the cooler.

— C.E. Power supply complies with European Union dire...ctives for energy efficiency and safety.

— CB. Power supply complies with IEC (International Electrotechnical Commission) directives regarding the safety of electrical equipment and components.

— FCC. Power supply complies with FCC (Federal Communications Commission) directives, especially regarding electromagnetic interference.

— CCC. Compliance of the power supply with the requirements necessary for official certification in the Chinese market (PRC).

— K.C. Compliance of the power supply with the requirements necessary for official certification in the South Korean market.

— BSMI. Compliance of the power supply with the requirements required for official certification in the Taiwan market.

— RCM. Power supply meets the requirements for official certification in the Australian and New Zealand market. RCM requirements are primarily concerned with safe use and electromagnetic compatibility.

— TUV-RH. Power supply meets the criteria for certification by TÜV Rheinland Group, one of the world's largest and most respected auditing and certification companies. Most often, we are talking about the TÜV-Mark Approval certificate, which indicates that the individual parts of the device (body, boards, parts, switches, etc.) comply with the requirements for safe use.

— cTUVus. Another certification held by the above mentioned TÜV Rheinland Group. In this case, we are talking about the compliance of the power supply with the technical requirements necessary for admission to the markets of the USA and Canada. The cTUVus certificate has the same legal validity as certificates issued directly by the authorities in those countries.

— EAC. Compliance of the power supply with the technical requirements of the Eurasian Economic Union (former Customs Union).

The noise level produced by the power supply.

Usually, the characteristics indicate the average value of the noise level during normal operation. The lower this value, the quieter the power supply and the more comfortable it is to use. However, it is worth noting that modern computer PSUs produce very little noise. So, in the quietest models, this figure does not exceed 20 dB — this is no louder than the rustling of leaves in a light breeze, such a sound is almost inaudible and is quite acceptable even in a residential area at night. Also acceptable for this application are noise sources of 21 – 25 dB(corresponding to a whisper at a distance of about 1 m) and 26 – 30 dB(wall clock ticking). Noise of more than 30 dB is already considered quite significant for computer PSUs; according to sanitary standards, such equipment in residential premises can only be used during the day.

When choosing a power supply for this indicator, it is worth considering a few points. First, noise reduction comes at a cost: it can affect the cooling performance and/or cost of the device. Secondly, the noise from the power supply is often lost against the background of louder PC components — for example, powerful cooling systems for the CPU or graphics card. Thirdly, the very environment where the PC is installed can be noisy — an example is a...n office or coworking. Thus, specifically looking for a low-noise model makes sense mainly in cases where maximum silence is crucial for you.

Manufacturer's warranty provided for this model.

In fact, this is the minimum service life promised by the manufacturer, subject to the rules of operation. There are both models with a small warranty up to 3 years, and more advanced power supplies, in which the warranty can reach 7, 10 years and even 12 years. In general , a 5-year warranty(for example) does not mean that the device will fail after the specified time. Most often, the actual service life of the device is much longer than the guaranteed one.

Specific warranty periods may vary even for similar drives from the same manufacturer. So not

The power supply has its own backlight. This function does not affect the technical characteristics, its role is purely aesthetic, and therefore it is worth paying attention to power supplies with backlight, first of all, for those who care about the individual design of their own PC. Note that the specific functionality of the backlight may be different. The simplest systems are single-colour, more expensive solutions may provide several colour options, and the most advanced type of backlight in this regard is RGB, with the ability to select almost any shade at the request of the user. In addition, some systems are able to synchronize with the backlight of other PC components; See "Light Timing" below for more on this.

Synchronization technology provided in the illuminated power supply (see above).

Synchronization itself allows you to “match” the backlight of the PSU with the backlight of other system components — the motherboard, processor, graphics card, case, keyboard, mouse, etc. Thanks to this matching, all components can change colour synchronously, turn on / off at the same time, etc. etc. The specific features of the operation of such a backlight depend on the synchronization technology used, and, usually, each manufacturer has its own (Aura Sync for Asus, RGB Fusion for Gigabyte, etc.). The compatibility of the components also depends on this: they must all support the same technology. So the easiest way to achieve backlight compatibility is to collect components from the same manufacturer. There are also power supplies with multi compatibility — that is, they support several synchronization standards at once; however, the specific set of compatible standards for such models may be different, it must be clarified before purchase.