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. Classic fan — a motor with blades that provides air flow; it also includes multi-fan kits. Anyway, you should not confuse such devices with coolers (see below) — fans do not have heatsinks. Almost all solutions of this type are designed for enclosures (see "Intended use"), only a few models are designed for "blowing" hard drives or chipsets.

— Radiator. Thermally conductive material construction with a special ribbed shape. This shape provides a large area of contact with air, as a result — good heat transfer. Radiators do not consume energy and operate absolutely silently, but they are not very efficient. Therefore, they are extremely rare in their pure form, 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).

— Active cooler. A device in the form of a radiator with a fan installed on it; however, in many models, the heatsink does not directly contact the cooled component, but is connected to it using heat pipes, while air is blown sideways (the so-called tower layout, especially popular in systems for the CPU; for more details, see "Blowing the air flow") . Anyway, such designs are, on the one hand, relatively simp...le and inexpensive, and, on the other hand, quite effective, which makes them an extremely popular type of Cooling system. In particular, it is in this format that most solutions for CPUs are produced (see "Intended use"), and in general coolers can be used for almost any component of the system, except for the case.

— Water cooling. Water cooling systems consist of three main parts: a water block in direct contact with the cooled component (usually a processor), an external cooler, and a pump (separate or built into the cooler). These components are connected by hoses through which water (or other similar coolant) circulates — it provides heat transfer. And the cooling block is usually a cooler — a system of fans and heatsinks that dissipates heat 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 can hardly cope with. On the other hand, this type of cooling is quite bulky and difficult to install, and it is not cheap.

— A set of LSS. Kit for self-assembly of liquid (water) cooling system. The difference between such solutions and conventional water cooling (see above) lies in the fact that in this case the entire system is supplied as a set of parts, from which the user must assemble the finished coolant himself (whereas in traditional water systems, the matter is usually limited to connecting hoses and filling coolant). Such a format significantly expands the user's options in terms of installation: you can independently choose individual layout nuances, replace some regular parts, supplement the design with third-party elements, etc. On the other hand, the installation itself turns out to be much more complex than traditional water systems. Therefore, very few LSS kits are produced, and they are designed mainly for enthusiast modders who like to experiment with the design and construction of their PCs.

— backplate. A solid metal plate used as a fastener for the cooling system. Serves to prevent the motherboard or video card from bending when deploying a heat dissipation system, and also provides passive cooling for the rear side of those modules with which it is adjacent.

- Water block VRM. A water block that provides efficient cooling of the elements of the VRM (Voltage Regulator Module) CPU power subsystem.

- CPU waterblock. Heat exchanger made of copper or nickel, designed to remove heat from the CPU through the coolant. Used in computer water cooling systems. Most often, processor water blocks are supplied with mounts for certain processor platforms.

- GPU water block. Liquid cooling blocks for the most efficient heat removal from the video card. Similar solutions are produced for a specific group of video cards on a single GPU. GPU water blocks consist of two main parts: the upper one, where a copper alloy heat sink is located, a plastic overlay with liquid channels and a casing to stiffen the structure, as well as a metal plate at the bottom of the block on the reverse side of the printed circuit board.

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

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 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.

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 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.