Comparison Noctua NH-U14S vs Noctua NF-A15 PWM

The component of a computer system for which the cooling system is designed.

Nowadays, two types of Cooling system are most widely used — for CPU and for the case. Other solutions are also being produced — for video cards, RAM, hard drives, etc.; however, in most cases, such computer components either do not require special cooling systems at all (hard drives are a typical example), or are equipped with them initially (video cards).

COs for CPUs most often have the format of an active cooler or a water cooling system (see "Type"). In this case, in both cases, the design usually provides for a substrate — a contact plate adjacent directly to the processor. Heat from the substrate is transferred to the cooling unit using heat pipes (in coolers) or a circuit with a circulating coolant (in liquid systems). Heatsinks are also produced for CPUs — they are designed mainly for low-power CPUs with low heat dissipation; when installing such a component, special attention should be paid to the quality of the cooling of the case.

In turn, COs for cases are made exclusively in the form of fans, since their task is not to cool a strictly defined component, but to remove hot air from the entire volume of the system unit.

- Fan. A classic fan is a motor with blades that provides air flow; This also includes sets of several fans. In any case, such devices should not be confused with coolers (see below) - fans do not have radiators. Almost all solutions of this type are designed for cases (see “Purpose”), only a few models are designed for “airflow” hard drives or chipsets.

— Reversible fan. A type of fan (see above) in which the impeller is turned in the opposite direction. This was done so that when placed behind the “system unit” case or in its upper part, it was possible to give the assembly an aesthetic appearance - the reversible fan will be installed with the front side for air airflow. Such solutions are used mainly for the side walls of “aquarium” type housings.

— Radiator. Design made of heat-conducting material with a special ribbed shape. This shape provides a large area of contact with air, and as a result, good heat transfer. Radiators do not consume energy and operate absolutely silently, but are not very efficient. Therefore, in their pure form they are extremely rare, and such models are intended either for low-power PC components with low heat dissipation (energy-efficient processors, hard drives, etc.), or for assembling an active cooler (see below) from a separately purchased fan and radiator (this option is found among solutions for video cards).
<...br> — Active cooler. A device in the form of a radiator with a fan installed on it; Moreover, in many models, the radiator does not directly contact the cooled component, but is connected to it using heat pipes, while air is blown out to the side (the so-called tower layout, especially popular in systems for CPU; for more details, see “Blowing air flow”) . In any case, such designs, on the one hand, are relatively simple and inexpensive, on the other hand, they are quite effective, making them an extremely popular type of CO. In particular, it is in this format that most solutions for processors are produced (including tower and boxed ones), and in general, coolers can be used for almost any component of the system, with the exception of the case.

- Water cooling. Water cooling systems consist of three main parts: a water block in direct contact with the component to be cooled (usually the processor), an external cooler, and a pump (either separate or built into the cooler). These components are connected by hoses through which water (or another similar coolant) circulates - it provides heat transfer. And the cooling unit is usually a cooler - a system of fans and radiators that dissipates thermal energy into the surrounding air. Water systems are noticeably more efficient than active coolers (see above); they are suitable even for very powerful and “hot” CPUs, which traditional coolers have difficulty coping with. On the other hand, this type of cooling is quite cumbersome and difficult to install, and is not cheap.

— LSS kit. Kit for self-assembly of a liquid (water) cooling system. In this case, it is understood that the entire system is supplied in the form of a set of parts, from which the customer must assemble the finished life-support system himself. Its installation is more complex than traditional water systems. Therefore, there are only a few LSS kits produced, and they are designed mainly for enthusiasts who like to experiment with the design and design of their PCs.

- Backplate. A solid metal plate used as a fastening element for the cooling system. Serves to prevent bending of the motherboard or video card when deploying a heat dissipation system, and also provides passive cooling of the rear side of tech modules with which it is adjacent.

— Water block VRM. A water block that provides effective cooling of the elements of the VRM (Voltage Regulator Module) power subsystem of the central processor.

— CPU water block. A copper or nickel heat exchanger designed to remove heat from the CPU through the coolant. Used in water cooling systems for computers. Most often, processor water blocks are equipped with mounts for specific processor platforms.

- GPU water block. Liquid cooling units for maximum efficient heat removal from the video card. Similar solutions are produced for a specific group of video cards on one graphics processor. GPU water blocks consist of two main parts: the top, where a copper alloy heat sink is located, a plastic cover with liquid channels and a casing to give rigidity to the structure, as well as a metal plate at the bottom of the block on the back side of the printed circuit board.

— A set of fastenings. A set of fasteners for mounting cooling systems on elements of a computer motherboard. Available for specific socket versions.

The direction in which the active cooler (see "Type") airflow exits.

This parameter is relevant primarily for models used with processors, but the options can be as follows:

— Sideways (scattering). Operation format typical for coolers of the so-called tower design. In these models, the fan is mounted perpendicular to the substrate in contact with the processor, due to which the airflow moves parallel to the motherboard. This ensures maximum efficiency: the heated air does not return to the processor and other system components, but is dissipated in the case (and almost immediately goes outside if the computer has at least one case fan). The main disadvantage of this option is the large height of the structure, which can make it difficult to place it in some system units. However, in most cases this point is not fundamental — especially when it comes to a powerful cooling system designed for an advanced system with a performant "hot" processor. So, it is side dissipation that is the most popular option nowadays — especially in coolers with a maximum TDP of 150 W and higher (although more modest models often use this layout).

— Down (to the motherboard). This format of operation allows you to "lay" the fan with a heatsink flat on the motherboard, significantly reducing the height of the entire cooler (compared to models using side blowing). On the other hand, this format of...work is not very efficient — after all, before dissipating through the case, hot air again blows over the board with the processor. So nowadays, this option is relatively rare, and mainly in low-power coolers with an acceptable TDP of up to 150 W. And you should pay attention to such models mainly when there is little space in the case and a small cooler height is more important than high efficiency.

The maximum TDP provided by the cooling system. Note that this parameter is indicated only for solutions equipped with heatsinks (see "Type"); for separately made fans, the efficiency is determined by other parameters, primarily by the air flow values (see above).

TDP can be described as the amount of heat that a cooling system is able to remove from a serviced component. Accordingly, for the normal operation of the entire system, it is necessary that the TDP of the cooling system is not lower than the heat dissipation of this component (heat dissipation data is usually indicated in the detailed characteristics of the components). And it is best to select coolers with a power margin of at least 20 – 25% — this will give an additional guarantee in case of forced operation modes and emergency situations (including clogging of the case and reduced air exchange efficiency).

As for specific numbers, the most modest modern cooling systems provide TDP up to 100 W, the most advanced — up to 250 W and even higher.

This parameter must be considered in the context of whether the fan will fit into the computer case. Standard case fans are available in the order of 25 mm in thickness. Low-profile coolers with a thickness of about 15 mm are designed for small-sized cases, where saving space is extremely important. Fans of large thickness (30-40 mm) boast high cooling efficiency due to the increased impeller dimensions. However, they are noisier than standard models at the same speed and do not always fit into the case normally, sometimes touching other components.

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.

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 ability to replace a regular fan by the user himself — without contacting a service centre or repairmen. The maximum that may be required for such a procedure is the simplest tools like a screwdriver; sometimes they are even initially included in the cooling system kit.

The fan, as the most mobile part of any cooling system, is more prone to breakdowns and failures than other parts. In cases like this, it's cheaper (and often smarter) to replace just that part rather than buying a whole new system. Also, if desired, you can change a working fan — for example, to a more powerful or less noisy one.