Often used to build a large radiator heat pipes(English: heat pipes) - hermetically sealed and specially arranged metal tubes (usually copper). They transfer heat very efficiently from one end to the other: thus, even the farthest fins of a large heatsink work effectively in cooling. So, for example, the popular cooler is arranged

To cool modern high-performance GPUs, the same methods are used: large radiators, copper core cooling systems or all-copper radiators, heat pipes to transfer heat to additional radiators:

Recommendations for choosing here are the same: use slow and large-sized fans, the largest possible heatsinks. So, for example, popular cooling systems for video cards and Zalman VF900 look like:

Usually, the fans of video card cooling systems only mixed the air inside the system unit, which is not very effective in terms of cooling the entire computer. Only very recently, cooling systems have been used to cool video cards that carry hot air outside the case: the first steels and a similar design from the brand:

Similar cooling systems are installed on the most powerful modern video cards (nVidia GeForce 8800, ATI x1800XT and older). Such a design is often more justified, in terms of the proper organization of air flows inside the computer case, than traditional schemes. Air flow organization

Modern standards for the design of computer cases, among other things, regulate the way the cooling system is built. Starting with, the release of which was launched in 1997, a computer cooling technology is being introduced with a through air flow directed from the front wall of the case to the back (additionally, air for cooling is sucked in through the left wall):

Those interested in the details are referred to the latest versions of the ATX standard.

At least one fan is installed in the computer's power supply (many modern models have two fans, which can significantly reduce the rotation speed of each of them, and, therefore, the noise during operation). Additional fans can be installed anywhere inside the computer case to increase airflow. Be sure to follow the rule: on the front and left side walls, air is blown into the case, on the back wall, hot air is thrown out. You also need to make sure that the flow of hot air from the rear wall of the computer does not fall directly into the air intake on the left wall of the computer (this happens at certain positions of the system unit relative to the walls of the room and furniture). Which fans to install depends primarily on the availability of appropriate mounts in the walls of the case. Fan noise is mainly determined by fan speed (see section ), so slow (quiet) fan models are recommended. With equal installation dimensions and rotational speed, the fans on the rear wall of the case are subjectively noisier than the front ones: firstly, they are farther from the user, and secondly, there are almost transparent grilles at the back of the case, while various decorative elements are at the front. Often noise is created due to air flow around the elements of the front panel: if the amount of air flow transferred exceeds a certain limit, eddy turbulent flows form on the front panel of the computer case, which create a characteristic noise (it resembles the hiss of a vacuum cleaner, but much quieter).

Choosing a computer case

Almost the vast majority of computer cases on the market today comply with one of the versions of the ATX standard, including in terms of cooling. The cheapest cases are not equipped with either a power supply or additional devices. More expensive cases are equipped with fans to cool the case, less often - adapters for connecting fans in various ways; sometimes even a special controller equipped with thermal sensors, which allows you to smoothly adjust the rotation speed of one or more fans depending on the temperature of the main components (see for example). The power supply is not always included in the kit: many buyers prefer to choose a PSU on their own. Of the other options for additional equipment, it is worth noting special fastenings for side walls, hard drives, optical drives, expansion cards that allow you to assemble a computer without a screwdriver; dust filters that prevent dirt from entering the computer through the ventilation holes; various nozzles for directing air flows inside the case. Exploring the fan

Used to transport air in cooling systems fans(English: fan).

Fan device

The fan consists of a housing (usually in the form of a frame), an electric motor and an impeller mounted with bearings on the same axis as the motor:

The reliability of the fan depends on the type of bearings installed. Manufacturers claim the following typical MTBF (number of years based on 24/7 operation):

Taking into account the obsolescence of computer equipment (for home and office use it is 2-3 years), fans with ball bearings can be considered "eternal": their life is not less than the typical life of a computer. For more serious applications, where the computer must work around the clock for many years, it is worth choosing more reliable fans.

Many have come across old fans in which the plain bearings have worn out their life: the impeller shaft rattles and vibrates during operation, making a characteristic growling sound. In principle, such a bearing can be repaired by lubricating it with solid lubricant - but how many will agree to repair a fan that costs only a couple of dollars?

Fan specifications

Fans vary in size and thickness: commonly found in computers are 40x40x10mm for cooling graphics cards and hard drive pockets, as well as 80x80x25, 92x92x25, 120x120x25mm for case cooling. Also, fans differ in the type and design of the installed electric motors: they consume different current and provide different impeller rotation speeds. The size of the fan and the speed of rotation of the impeller blades determine the performance: the generated static pressure and the maximum volume of air transferred.

The volume of air carried by a fan (flow rate) is measured in cubic meters per minute or cubic feet per minute (CFM). The performance of the fan, indicated in the characteristics, is measured at zero pressure: the fan operates in an open space. Inside the computer case, the fan blows into the system unit of a certain size, so it creates excess pressure in the serviced volume. Naturally, the volumetric efficiency will be approximately inversely proportional to the pressure generated. specific kind flow characteristics depends on the shape of the used impeller and other parameters of a particular model. For example, the corresponding graph for a fan is:

From this follows a simple conclusion: the more intense the fans in the back of the computer case, the more air can be pumped through the entire system, and the more efficient the cooling will be.

Fan noise level

The noise level created by the fan during operation depends on its various characteristics (more details about the reasons for its occurrence can be found in the article). It is easy to establish the relationship between performance and fan noise. On the website of a large manufacturer of popular cooling systems, we see: many fans of the same size are equipped with different electric motors, which are designed for different rotation speeds. Since the same impeller is used, we obtain the data we are interested in: the characteristics of the same fan at different rotation speeds. We compile a table for the three most common sizes: thickness 25 mm, and.

Bold font indicates the most popular types of fans.

Having calculated the coefficient of proportionality of the air flow and the noise level to the speed, we see an almost complete match. To clear our conscience, we consider deviations from the average: less than 5%. Thus, we got three linear dependencies, 5 points each. Not God knows what kind of statistics, but this is enough for a linear dependence: we consider the hypothesis confirmed.

The volumetric efficiency of the fan is proportional to the number of revolutions of the impeller, the same is true for the noise level.

Using the obtained hypothesis, we can extrapolate the obtained results using the least squares method (LSM): in the table, these values ​​are marked in italics. However, it must be remembered that the scope of this model is limited. The investigated dependence is linear in a certain range of rotation speeds; it is logical to assume that the linear nature of the dependence will remain in some neighborhood of this range; but at very high and very low speeds, the picture can change significantly.

Now consider the line of fans from another manufacturer:, and. Let's create a similar table:

Calculated data are marked in italics.
As mentioned above, at fan speeds that differ significantly from those studied, the linear model may be incorrect. The values ​​obtained by extrapolation should be understood as a rough estimate.

Let's pay attention to two circumstances. Firstly, GlacialTech fans are slower, and secondly, they are more efficient. Obviously, this is the result of using an impeller with a more complex blade shape: even at the same speed, the GlacialTech fan carries more air than the Titan: see graph growth. BUT the noise level at the same speed is approximately equal to: the proportion is observed even for fans of different manufacturers with different impeller shapes.

It should be understood that the real noise characteristics of a fan depend on its technical design, the pressure generated, the volume of air pumped, on the type and shape of obstacles in the way of air flows; that is, on the type of computer case. Since there are a wide variety of cases used, it is impossible to directly apply the quantitative characteristics of fans measured under ideal conditions - they can only be compared with each other for different fan models.

Price categories of fans

Consider the cost factor. For example, let's take and in the same online store: the results are entered in the tables above (fans with two ball bearings were considered). As you can see, the fans of these two manufacturers belong to two different classes: GlacialTech operate at lower speeds, so they make less noise; at the same speed they are more efficient than Titan - but they are always more expensive by a dollar or two. If you need to build the least noisy cooling system (for example, for a home computer), you will have to fork out for more expensive fans with complex blade shapes. In the absence of such strict requirements or with a limited budget (for example, for an office computer), simpler fans will do just fine. The different type of impeller suspension used in fans (for more details, see section ) also affects the cost: the fan is more expensive, the more complex bearings are used.

The connector key is beveled corners on one side. The wires are connected as follows: two central ones - "ground", common contact (black wire); +5 V - red, +12 V - yellow. To power the fan through the molex connector, only two wires are used, usually black ("ground") and red (supply voltage). By connecting them to different pins of the connector, you can get different fan speeds. A standard voltage of 12V will run the fan at normal speed, a voltage of 5-7V provides about half the rotation speed. It is preferable to use a higher voltage, since not every electric motor is able to reliably start at too low a supply voltage.

As experience shows, fan speed when connected to +5 V, +6 V and +7 V is approximately the same(with an accuracy of 10%, which is comparable to the accuracy of measurements: the rotation speed is constantly changing and depends on many factors, such as air temperature, the slightest draft in the room, etc.)

I remind you that the manufacturer guarantees the stable operation of its devices only when using a standard supply voltage. But, as practice shows, the vast majority of fans start up perfectly even at low voltage.

The contacts are fixed in the plastic part of the connector with a pair of folding metal "antennae". It is not difficult to remove the contact by pressing down the protruding parts with a thin awl or a small screwdriver. After that, the "antennae" must again be unbent to the sides, and insert the contact into the corresponding socket of the plastic part of the connector:

Sometimes coolers and fans are equipped with two connectors: a molex connected in parallel and a three- (or four-) pin. In this case you need to connect power only through one of them:

In some cases, not one molex connector is used, but a pair of "mom-dad": this way you can connect the fan to the same wire from the power supply that powers the hard drive or optical drive. If you are swapping the pins in the connector to get a non-standard voltage on the fan, pay special attention to swap the pins in the second connector in exactly the same order. Failure to do so will result in the wrong voltage being supplied to the hard drive or optical drive, which will most likely result in their immediate failure.

In three-pin connectors, the installation key is a pair of protruding guides on one side:

The mating part is located on the contact pad; when connected, it enters between the guides, also acting as a retainer. The corresponding connectors for powering the fans are located on the motherboard (usually several pieces in different places on the board) or on the board of a special controller that controls the fans:

In addition to the "ground" (black wire) and +12 V (usually red, less often: yellow), there is also a tachometric contact: it is used to control the fan speed (white, blue, yellow or green wire). If you do not need the ability to control the fan speed, then this contact can be omitted. If the fan is powered separately (for example, via a molex connector), it is permissible to connect only the speed control contact and a common wire using a three-pin connector - this scheme is often used to monitor the fan speed of the power supply, which is powered and controlled by the internal circuits of the PSU.

Four-pin connectors have appeared relatively recently on motherboards with processor sockets LGA 775 and socket AM2. They differ in the presence of an additional fourth contact, while being fully mechanically and electrically compatible with three-pin connectors:

Two identical fans with three-pin connectors can be connected in series to one power connector. Thus, each of the electric motors will have 6 V of supply voltage, both fans will rotate at half speed. For such a connection, it is convenient to use fan power connectors: the contacts can be easily removed from the plastic case by pressing the fixing “tab” with a screwdriver. The connection diagram is shown in the figure below. One of the connectors connects to the motherboard as usual: it will provide power to both fans. In the second connector, using a piece of wire, you need to short-circuit two contacts, and then insulate it with tape or electrical tape:

It is strongly not recommended to connect two different electric motors in this way.: due to the inequality of electrical characteristics in various operating modes (startup, acceleration, stable rotation), one of the fans may not start at all (which is fraught with failure of the electric motor) or require an excessively high current to start (it is fraught with failure of the control circuits).

Often, fixed or variable resistors connected in series in the power circuit are used to limit the fan speed. By changing the resistance of the variable resistor, you can adjust the rotation speed: this is how many manual fan speed controllers are arranged. When designing such a circuit, it must be remembered that, firstly, the resistors heat up, dissipating part of the electrical power in the form of heat - this does not contribute to more efficient cooling; secondly, the electrical characteristics of the electric motor in various operating modes (starting, acceleration, stable rotation) are not the same, the resistor parameters must be selected taking into account all these modes. To select the parameters of the resistor, it is enough to know Ohm's law; you need to use resistors designed for a current no less than the electric motor consumes. However, I personally do not welcome manual control of cooling, as I believe that a computer is quite a suitable device to control the cooling system automatically, without user intervention.

Fan monitoring and control

Most modern motherboards allow you to control the speed of fans connected to some three- or four-pin connectors. Moreover, some of the connectors support software control of the speed of rotation of the connected fan. Not all connectors on the board provide such capabilities: for example, the popular Asus A8N-E board has five connectors for powering fans, only three of them support rotation speed control (CPU, CHIP, CHA1), and only one fan speed control (CPU); Asus P5B motherboard has four connectors, all four support rotation speed control, rotation speed control has two channels: CPU, CASE1 / 2 (the speed of two case fans changes synchronously). The number of connectors with the ability to control or control the speed of rotation does not depend on the chipset or southbridge used, but on the specific model of the motherboard: models from different manufacturers may differ in this regard. Often, motherboard designers deliberately deprive cheaper models of fan speed control capabilities. For example, the Asus P4P800 SE motherboard for Intel Pentiun 4 processors is able to regulate the speed of the processor cooler, while its cheaper version Asus P4P800-X is not. In this case, you can use special devices that are able to control the speed of several fans (and usually provide for the connection of a number of temperature sensors) - there are more and more of them on the modern market.

Fan speeds can be controlled using BIOS Setup. As a rule, if the motherboard supports changing the fan speed, here in the BIOS Setup you can configure the parameters of the speed control algorithm. The set of parameters is different for different motherboards; usually the algorithm uses the readings of thermal sensors built into the processor and motherboard. There are a number of programs for various operating systems that allow you to control and adjust the speed of fans, as well as monitor the temperature of various components inside the computer. Manufacturers of some motherboards bundle their products with proprietary programs for Windows: Asus PC Probe, MSI CoreCenter, Abit µGuru, Gigabyte EasyTune, Foxconn SuperStep, etc. Several universal programs are distributed, among them: (shareware, $20-30), (distributed free of charge, not updated since 2004). The most popular program of this class is:

These programs allow you to monitor a number of temperature sensors that are installed in modern processors, motherboards, video cards and hard drives. The program also monitors the rotation speed of fans that are connected to the motherboard connectors with the appropriate support. Finally, the program is able to automatically adjust the speed of the fans depending on the temperature of the observed objects (if the motherboard manufacturer has implemented hardware support for this feature). In the figure above, the program is configured to control only the processor fan: at a low CPU temperature (36°C), it rotates at a speed of about 1000 rpm, which is 35% of the maximum speed (2800 rpm). Setting up such programs comes down to three steps:

  1. determining which of the channels of the motherboard controller are connected to fans, and which of them can be controlled by software;
  2. specifying which temperatures should affect the speed of the various fans;
  3. setting temperature thresholds for each temperature sensor and operating speed range for fans.

Many programs for testing and fine-tuning computers also have monitoring capabilities:, etc.

Many modern video cards also allow you to adjust the speed of the cooling fan depending on the temperature of the GPU. With the help of special programs, you can even change the settings of the cooling mechanism, reducing the noise level from the video card in the absence of load. This is how the optimal settings for the HIS X800GTO IceQ II video card look in the program:

Passive cooling

Passive cooling systems are called those that do not contain fans. Individual computer components can be content with passive cooling, provided that their heatsinks are placed in sufficient airflow created by "foreign" fans: for example, a chipset chip is often cooled by a large heatsink located near the CPU cooler. Passive cooling systems for video cards are also popular, for example:

Obviously, the more heat sinks one fan has to blow through, the more flow resistance it needs to overcome; thus, with an increase in the number of radiators, it is often necessary to increase the speed of rotation of the impeller. It is more efficient to use a lot of low-speed large-diameter fans, and passive cooling systems are preferably avoided. Despite the fact that passive heatsinks for processors, video cards with passive cooling, even power supplies without fans (FSP Zen) are produced, trying to build a computer without fans at all from all these components will certainly lead to constant overheating. Because a modern high-performance computer dissipates too much heat to be cooled only by passive systems. Due to the low thermal conductivity of air, it is difficult to organize effective passive cooling for the entire computer, except to turn the entire computer case into a radiator, as is done in:

Compare the case-radiator in the photo with the case of a conventional computer!

Perhaps, completely passive cooling will be enough for low-power specialized computers (for Internet access, for listening to music and watching videos, etc.)

In the old days, when the power consumption of processors had not yet reached critical values ​​- a small radiator was enough to cool them - the question "what will the computer do when nothing needs to be done?" It was solved simply: while it is not necessary to execute user commands or running programs, the OS gives the processor a NOP command (No OPeration, no operation). This command causes the processor to perform a meaningless, ineffectual operation, the result of which is ignored. This takes not only time, but also electricity, which, in turn, is converted into heat. A typical home or office computer, in the absence of resource-intensive tasks, is usually only 10% loaded - anyone can verify this by launching the Windows Task Manager and watching the CPU (Central Processing Unit) Load History. Thus, with the old approach, about 90% of the processor time flew to the wind: the CPU was busy executing commands that no one needed. Newer operating systems (Windows 2000 and later) act smarter in a similar situation: using the HLT (Halt, stop) command, the processor is completely stopped for a short time - this obviously allows you to reduce power consumption and processor temperature in the absence of resource-intensive tasks.

Experienced computer scientists can recall a number of "software processor cooling" programs: when running under Windows 95/98/ME, they stopped the processor using HLT, instead of repeating meaningless NOPs, which lowered the processor temperature in the absence of computational tasks. Accordingly, the use of such programs under Windows 2000 and newer operating systems is meaningless.

Modern processors consume so much energy (which means: they dissipate it in the form of heat, that is, they heat up) that the developers have created additional technical measures to combat possible overheating, as well as tools that increase the efficiency of saving mechanisms when the computer is idle.

CPU thermal protection

To protect the processor from overheating and failure, the so-called thermal throttling is used (usually not translated: throttling). The essence of this mechanism is simple: if the processor temperature exceeds the allowable one, the processor is forcibly stopped by the HLT command so that the crystal has the opportunity to cool down. In early implementations of this mechanism, through BIOS Setup, it was possible to configure how much time the processor would be idle (CPU Throttling Duty Cycle: xx%); new implementations "slow down" the processor automatically until the temperature of the crystal drops to an acceptable level. Of course, the user is interested in the fact that the processor does not cool down (literally!), but does useful work - for this you need to use a fairly efficient cooling system. You can check if the processor thermal protection mechanism (throttling) is enabled using special utilities, for example:

Minimization of energy consumption

Almost all modern processors support special technologies to reduce energy consumption (and, accordingly, heating). Different manufacturers call such technologies differently, for example: Enhanced Intel SpeedStep Technology (EIST), AMD Cool'n'Quiet (CnQ, C&Q) - but they work, in fact, the same way. When the computer is idle and the processor is not loaded with computing tasks, the clock frequency and voltage of the processor decreases. Both of these reduce the power consumption of the processor, which in turn reduces heat dissipation. As soon as the processor load increases, the full speed of the processor is automatically restored: the operation of such a power saving scheme is completely transparent to the user and running programs. To enable such a system, you need:

  1. enable the use of supported technology in BIOS Setup;
  2. install the appropriate drivers in the OS you are using (usually this is a processor driver);
  3. in the Windows Control Panel, in the Power Management section, on the Power Schemes tab, select the Minimal Power Management scheme from the list.

For example, for an Asus A8N-E motherboard with a processor, you need (detailed instructions are in the User's Guide):

  1. in BIOS Setup, in the Advanced > CPU Configuration > AMD CPU Cool & Quiet Configuration section, switch the Cool N "Quiet parameter to Enabled; and in the Power section, switch the ACPI 2.0 Support parameter to Yes;
  2. install ;
  3. see above.

You can check that the processor frequency is changing using any program that displays the processor clock speed: from specialized types, up to the Windows Control Panel (Control Panel), section System (System):


AMD Cool "n" Quiet in action: current CPU frequency (994 MHz) is lower than nominal (1.8 GHz)

Often, motherboard manufacturers additionally complete their products with visual programs that clearly demonstrate the operation of the mechanism for changing the frequency and voltage of the processor, for example, Asus Cool&Quiet:

The processor frequency changes from maximum (in the presence of computational load) to some minimum (in the absence of CPU load).

RMClock utility

During the development of a set of programs for complex testing of processors, (RightMark CPU Clock / Power Utility) was created: it is designed to monitor, configure and manage the power-saving capabilities of modern processors. The utility supports all modern processors and a variety of power consumption management systems (frequency, voltage ...). The program allows you to monitor the occurrence of throttling, changes in the frequency and voltage of the processor. Using RMClock, you can configure and use everything that standard tools allow: BIOS Setup, power management by the OS using the processor driver. But the possibilities of this utility are much wider: with its help, you can configure a number of parameters that are not available for configuration in a standard way. This is especially important when using overclocked systems, when the processor runs faster than the nominal frequency.

Video card auto overclocking

A similar method is used by video card developers: the full power of the GPU is needed only in 3D mode, and a modern graphics chip can cope with a desktop in 2D mode even at a reduced frequency. Many modern video cards are tuned so that the graphics chip serves the desktop (2D mode) with reduced frequency, power consumption and heat dissipation; accordingly, the cooling fan spins more slowly and makes less noise. The video card only starts to work at full capacity when running 3D applications, such as computer games. Similar logic can be implemented programmatically, using various utilities for fine-tuning and overclocking video cards. For example, this is how the automatic overclocking settings in the program for the HIS X800GTO IceQ II video card look like:

Quiet computer: myth or reality?

From the user's point of view, a sufficiently quiet computer will be considered such, the noise of which does not exceed the ambient background noise. During the day, taking into account the noise of the street outside the window, as well as the noise in the office or at work, it is permissible for the computer to make a little more noise. A home computer that is planned to be used around the clock should be quieter at night. As practice has shown, almost any modern powerful computer can be made to work quite quietly. I will describe a few examples from my practice.

Example 1: Intel Pentium 4 platform

My office uses 10 3.0 GHz Intel Pentium 4 computers with standard CPU coolers. All machines are assembled in inexpensive Fortex cases priced up to $30, Chieftec 310-102 power supplies (310 W, 1 80×80×25 mm fan) are installed. In each case, a 80x80x25 mm fan (3000 rpm, noise 33 dBA) was installed on the back wall - they were replaced by fans with the same performance 120x120x25 mm (950 rpm, noise 19 dBA) ). In the LAN file server, for additional cooling of hard drives, 2 80 × 80 × 25 mm fans are installed on the front wall, connected in series (speed 1500 rpm, noise 20 dBA). Most computers use the Asus P4P800 SE motherboard, which is able to regulate the speed of the processor cooler. Two computers have cheaper Asus P4P800-X boards, where the cooler speed is not regulated; to reduce noise from these machines, the CPU coolers have been replaced (1900 rpm, 20 dBA noise).
Result: computers are quieter than air conditioners; they are almost inaudible.

Example 2: Intel Core 2 Duo Platform

A home computer based on a new Intel Core 2 Duo E6400 (2.13 GHz) processor with a standard processor cooler was assembled in an inexpensive $25 aigo case, a Chieftec 360-102DF power supply (360 W, 2 80 × 80 × 25 mm fans) was installed. There are 2 fans 80×80×25 mm connected in series in the front and rear walls of the case (speed adjustable, from 750 to 1500 rpm, noise up to 20 dBA). Used motherboard Asus P5B, which is able to regulate the speed of the CPU cooler and case fans. A video card with a passive cooling system is installed.
Result: the computer makes such a noise that during the day it is not audible over the usual noise in the apartment (conversations, steps, the street outside the window, etc.).

Example 3: AMD Athlon 64 Platform

My home computer with an AMD Athlon 64 3000+ (1.8 GHz) processor was assembled in an inexpensive Delux case priced under $30, initially containing a CoolerMaster RS-380 power supply (380 W, 1 fan 80 × 80 × 25 mm) and a GlacialTech SilentBlade video card GT80252BDL-1 connected to +5 V (about 850 rpm, less than 17 dBA noise). The Asus A8N-E motherboard is used, which is able to regulate the speed of the processor cooler (up to 2800 rpm, noise up to 26 dBA, in idle mode the cooler rotates about 1000 rpm and noise is less than 18 dBA). The problem with this motherboard: cooling of the nVidia nForce 4 chipset chip, Asus installs a small 40x40x10 mm fan with a rotation speed of 5800 rpm, which whistles quite loudly and unpleasantly (in addition, the fan is equipped with a sleeve bearing that has a very short life) . To cool the chipset, a cooler for video cards with a copper radiator was installed; against its background, clicks of the positioning of the hard disk heads are clearly audible. A working computer does not interfere with sleeping in the same room where it is installed.
Recently, the video card was replaced by HIS X800GTO IceQ II, for the installation of which it was necessary to modify the chipset heatsink: bend the fins so that they do not interfere with the installation of a video card with a large cooling fan. Fifteen minutes of work with pliers - and the computer continues to work quietly even with a fairly powerful video card.

Example 4: AMD Athlon 64 X2 Platform

A home computer based on an AMD Athlon 64 X2 3800+ processor (2.0 GHz) with a processor cooler (up to 1900 rpm, noise up to 20 dBA) is assembled in a 3R System R101 case (2 fans 120 × 120 × 25 mm are included, up to 1500 rpm, installed on the front and rear walls of the case, connected to the standard monitoring and automatic fan control system), FSP Blue Storm 350 power supply (350 W, 1 fan 120 × 120 × 25 mm) is installed. A motherboard was used (passive cooling of the chipset microcircuits), which is able to regulate the speed of the processor cooler. Used graphics card GeCube Radeon X800XT, cooling system replaced by Zalman VF900-Cu. A hard drive was chosen for the computer, known for its low noise level.
Result: The computer is so quiet that you can hear the sound of the hard drive motor. A working computer does not interfere with sleeping in the same room where it is installed (the neighbors behind the wall are talking even louder).