Power
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).
PFC
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
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").
ATX12V version
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.
MB/CPU power supply
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.
MOLEX
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.
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.
