Comparison Deepcool XFAN 80L vs Noctua NF-B9

The diameter of the fan(s) used in the cooling system.

In general, larger fans are considered more advanced than smaller ones: they allow you to create a powerful air flow at a relatively low speed and low noise level. On the other hand, a large diameter means large dimensions, weight and price. As for specific figures, 40 mm and 60 mm models are considered miniature, 80 mm and 92 mm are medium, 120 mm and 135 / 140 mm are large, and even 200 mm fans are found in the most powerful case systems.

The highest speed at which the cooling system fan is capable of operating; for models without a speed controller (see below), this item indicates the nominal rotation speed. In the "slowest" modern fans, the maximum speed does not exceed 1000 rpm, in the "fastest" it can be up to 2500 rpm and even more.

Note that this parameter is closely related to the fan diameter (see above): the smaller the diameter, the higher the speed must be to achieve the desired airflow values. In this case, the rotation speed directly affects the level of noise and vibration. Therefore, it is believed that the required volume of air is best provided by large and relatively "slow" fans; and it makes sense to use "fast" small models where compactness is crucial. If we compare the speed of models of the same size, then higher speeds have a positive effect on performance, but increase not only the noise level, but also the price and power consumption.

— Auto (PWM). A type of automatic regulator used in processor cooling systems. The principle of this adjustment is that the automation monitors the current load on the CPU and adjusts the fan operation mode to it. Thus, the cooling system works "in advance": it actually prevents the temperature rise, and does not eliminate it (unlike the thermostat described below). The disadvantages of such automation are the high cost and additional compatibility requirements: the PWM function must be supported by the motherboard, and the fan must be powered through a 4-pin connector (see "Power").

— Manual. Manual regulator that allows you to set the rotation speed at the request of the user. Its main advantages are both the possibility of arbitrary adjustment and reliability: automation does not always respond optimally, and in performant systems it is sometimes better for the user to take control into his own hands. On the other hand, manual control is more expensive and also more difficult to use — it requires the user to pay more attention to the state of the system, and if not attentive, the likelihood of overheating increases significantly.

— Manual / auto. A combination of the two systems described above: the main control is carried out by PWM, and the manual regulator serves to limit the maximum rotational speed. A fairly convenient and advanced option that expands the possibilities of auto-adjustment and at the same time...does not require constant temperature control, as with a purely manual setting. However such functionality is expensive.

— Adapter (resistor). In this case, the speed is adjusted by reducing the voltage supplied to the fan. To do this, it is connected to the power supply through a resistor adapter. This is a kind of alternative to manual adjustment: adapters are inexpensive. On the other hand, they are much less convenient: the only way to change the rotation speed with such an adjustment is to actually change the adapter, and for this you have to turn off the system and climb into the case.

— Thermostat. Automatic speed control according to data from a sensor that measures the temperature of the cooled component: when the temperature rises, the intensity of work also increases, and vice versa. Such systems are simpler than the PWMs described above, moreover, they can be used for almost any system component, not only for CPU. On the other hand, they have more inertia and reaction time: if the PWM prevents heating in advance, then the thermostat is triggered by an increase in temperature that has already happened.

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.

The total time that a cooling fan is guaranteed to run before it fails. Note that when this time is exhausted, the device will not necessarily break — many modern fans have a significant margin of safety and are able to work for some more period. At the same time, it is worth evaluating the overall durability of the cooling system according to this parameter.

The presence of its own illumination in the design of the cooling system.

The backlight serves a purely aesthetic function — it gives the device a stylish appearance that blends well with other components in the original design. Thanks to this, such cooling systems are especially appreciated by gamers and fans of external PC modding — especially since the lighting can be different, and the most advanced models even provide backlight synchronization with other components (see below). On the other hand, this function does not affect the efficiency and performance, and the overall cost is inevitably affected, sometimes quite noticeably. Therefore, if the appearance does not play a fundamental role for you, the best choice, most likely, will be a cooling system without backlight.

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 e...xclusively in them.

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.

— 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 (adhesive 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.