Max. air flow
The maximum airflow that a cooling fan can create; measured in CFM — cubic feet per minute.
The higher the CFM number, the more efficient the fan. On the other hand, high performance requires either a large diameter (which affects the size and cost) or high speed (which increases the noise and vibration levels). Therefore, when choosing, it makes sense not to chase the maximum air flow, but to use special formulas that allow you to calculate the required number of CFM depending on the type and power of the cooled component and other parameters. Such formulas can be found in special sources. As for specific numbers, in the most modest systems, the performance
does not exceed 30 CFM, and in the most powerful systems it can be up to 80 CFM and even
more.
It is also worth considering that the actual value of the air flow at the highest speed is usually lower than the claimed maximum; see Static Pressure for details.
Starting voltage
The starting voltage of the fan installed in the cooling system. In fact, this is the smallest value necessary for stable operation of the fan — if the voltage is too low, it simply “will not start”. Note that this parameter is relevant mainly for rather specific tasks — for example, installing a fan in a power supply unit with a direct connection to the PSU, or choosing an external controller to control the rotation speed. When connected through standard power connectors, you can not pay much attention to the starting voltage.
Noise level
The standard noise level generated by the cooling system during operation. Usually, this paragraph indicates the maximum noise during normal operation, without overloads and other "extreme".
Note that the noise level is indicated in decibels, and this is a non-linear value. So it is easiest to evaluate the actual loudness using comparative tables. Here is a table for values found in modern cooling systems:
20 dB — barely audible sound (quiet whisper of a person at a distance of about 1 m, sound background in an open field outside the city in calm weather);
25 dB — very quiet (normal whisper at a distance of 1 m);
30 dB — quiet (wall clock). It is this noise that, according to sanitary standards, is the maximum allowable for constant sound sources at night (from 23.00 to 07.00). This means that if the computer is planned to sit at night, it is desirable that the volume of the cooling system does not exceed this value.
35 dB — conversation in an undertone, sound background in a quiet library;
40 dB — conversation, relatively quiet, but already in full voice. The maximum permissible noise level for residential premises in the daytime, from 7.00 to 23.00, according to sanitary standards. However, even the noisiest cooling systems usually do not reach this indicator, the maximum for such equipment is about 38 – 39 dB.
Lighting colour
The colour of the backlight installed in the cooling system.
See above for more details on the backlight itself. Also note here that in the illumination of modern cooling systems there is both one colour (most often
red or
blue, less often
green,
yellow,
white or
purple), and multi-colour systems such as
RGB and
ARGB. The choice of a single-colour backlight depends mainly on aesthetic preferences, but the last two varieties should be touched upon separately.
The basic principle of operation of both RGB and ARGB systems is the same: the design provides for a set of LEDs of three basic colours — red (Red), green (Green) and blue (Blue), and by changing the number and brightness of the included LEDs, you can not only intensity, but and tint of light. The difference between these options differs in functionality: RGB systems support a limited set of colours (usually up to one and a half dozen, or even less), while ARGB allows you to choose almost any shade from the entire available colour range. At the same time, both of them can support backlight synchronization (see below); in general, this function is not required for RGB and ARGB systems, but it is used almost exclusively in them.
Mount type
—
Latches. The simplest and most convenient type of fastening, in particular due to the fact that it does not require the use of additional tools. Plus, you don't need to remove the motherboard for snap-on installation.
— Double-
sided (backplate). This type of fastening is used in the most powerful and, as a result, heavy and large-sized cooling systems. Its feature is the presence of a plate installed on the opposite side of the motherboard — this plate is designed to protect against damage and so that the board does not bend under the weight of the structure.
—
Bolts. Fastening with classic bolts. It is considered somewhat more reliable than latches (see above), but less convenient, because. You can remove and install the cooling system only with a screwdriver. To date, bolts are mainly used to fasten case fans, as well as cooling systems for RAM and hard drives (see "Type", "Purpose").
—
Silicone mounts. The main advantage of silicone fasteners is good vibration absorption, which significantly reduces the noise level compared to similar systems using other types of fasteners. On the other hand, silicone is somewhat less reliable than bolts, so both types of fasteners are usually supplied in the kit, and the user chooses which ones to use.
— Adhesive tape. Fastening with adhesive tape (adhesi
...ve tape), usually double-sided. The main advantages of this mount are ease of use and compactness. On the other hand, it is difficult to remove such a cooling system. In addition, adhesive tape is inferior in thermal conductivity to the same thermal paste.