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").
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.
+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.
