Comparison Aerocool SFX SX-400 vs Aerocool Value VX-400

The form factor determines, first of all, the dimensions, and, as a result, the purpose of the power supply. To date, there are such main form factors:

— ATX. Conventionally, it can be called "standard" — this is the most common form factor for regular-sized desktop PCs (in Full Tower and Midi Tower cases).

— TFX. Compact form factor, designed specifically for small cases (in particular, Mini Tower). Due to their intended use, these power supplies are typically lower than full-sized ATX power supplies, while electrically they are fully ATX compliant.

— SFX. Modification of the ATX form factor, developed at the end of the 20th century as a power supply option for systems in miniature microATX and FlexATX form factors (the S in the name stands for "small", i.e. "small"). Accordingly, the main difference is the dimensions: they are much smaller and amount to (width-depth-height) 100x125x64 mm with a standard 60 mm fan. When installing larger or smaller fans, the height of the unit changes accordingly; there are other deviations from the standard (for example, a slightly greater depth). The power connectors are almost identical to the original ATX, and these two standards are considered completely interchangeable.

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").

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 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.

The number of 6-pin (6pin) PCI-E power connectors provided in the power supply.

Such connectors are used for additional power supply of 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). The 6-pin connector on the power supply additionally provides another 75 W — thus, when using this connector, it becomes possible to connect boards with a power consumption of up to 150 W.

Note that some video cards have several connectors for additional power at once. Thus, the PSU can provide both one PCI-E 6pin plug, and two such connectors. However, in general, this type of plug is used quite rarely — this is due to the spread of a more convenient and versatile 8pin connector in the “6 + 2” format, which can be used both as six- and eight-pin (see below for more details).

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.

The noise level produced by the power supply.

Usually, the characteristics indicate the average value of the noise level during normal operation. The lower this value, the quieter the power supply and the more comfortable it is to use. However, it is worth noting that modern computer PSUs produce very little noise. So, in the quietest models, this figure does not exceed 20 dB — this is no louder than the rustling of leaves in a light breeze, such a sound is almost inaudible and is quite acceptable even in a residential area at night. Also acceptable for this application are noise sources of 21 – 25 dB(corresponding to a whisper at a distance of about 1 m) and 26 – 30 dB(wall clock ticking). Noise of more than 30 dB is already considered quite significant for computer PSUs; according to sanitary standards, such equipment in residential premises can only be used during the day.

When choosing a power supply for this indicator, it is worth considering a few points. First, noise reduction comes at a cost: it can affect the cooling performance and/or cost of the device. Secondly, the noise from the power supply is often lost against the background of louder PC components — for example, powerful cooling systems for the CPU or graphics card. Thirdly, the very environment where the PC is installed can be noisy — an example is a...n office or coworking. Thus, specifically looking for a low-noise model makes sense mainly in cases where maximum silence is crucial for you.