Comparison Chieftec Atmos CPX-850FC vs Chieftec Polaris PPS-850FC

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").

— Active cooling system. Uses a fan that constantly operates to remove heat from internal components. Unlike passive cooling, the active system provides better heat dissipation and stability under high loads, preventing overheating. However, it creates noise. To eliminate this, fans in such power supplies can have dynamic speed control (AFC – Automatic Fan Control), reducing speed at low power consumption.

— Semi-passive. Active cooling systems with automatic fan shutdown in situations where the load on the power supply is low and heat generation is reduced. Let us remind you that systems of this type are more efficient than passive ones, but they consume additional energy and create noise during operation. Accordingly, at low loads, when intensive cooling is not required, it is wiser to turn off the fans — this saves energy and reduces the noise level.

— Passive(radiators). Compared to fans, radiators have a number of advantages: for example, they do not create any noise and do not require their own power supply (thus reducing overall energy consumption). On the other hand, they are significantly less efficient, as a result — the power of power supplies with passive cooling does not exceed 600 W. In addition, such power supplies 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.

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 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 16-pin PCIe 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 watts of additional power, which is a fourfold increase in power compared to the 8-pin versions of the interface. Additional PCIe connectors of all formats are used to power those types of internal peripherals that no longer have enough with the 75 watts delivered directly through the PCIe slot on the motherboard.

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.