Efficiency
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").
Cooling system
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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").
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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.
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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.Fan size
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.
SATA
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.
PCI-E 8pin (6+2)
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.
+3.3V
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.
+5V
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.
+3.3V +5V
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.
Protection
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).
