Cooling system
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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.
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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.
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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.
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.
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.
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.
Floppy
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.
-12V
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).
+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.
-12V
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.
