How much heat is generated by the system unit of my PC.

How much heat does the system unit of my PC give off? As much as it consumes electricity.
If we add up the passport and estimated figures for my configuration:

Processor AMD Athlon XP 3000+ ~ 65

DFI motherboard with nF4~20

DDR memory modules (2x1Gb) ~ 20

Video card GF6600GT SP II ~ 60

SATA hard drive 80 GB ~ 7

DVD drive - ROM ~ 5

The total power of the components - 177

Thermal losses of PSU with efficiency 0.9 - 18

Grand total - 195

Is it real? Due to the lack of an ammeter, I measured the real energy consumption using an apartment electric meter (fortunately, I have it in my apartment). It says: 625 r = 1k W * h , i.e. 1 kWh = 625 disk revolutions.
Therefore, if in Tsec seconds the disk rotates N revolutions, then
consumed energy [kWh]
E \u003d 1 * (N / 625)
and power [W]
P = E / Th * 1000 = (N / 625) / (Tsec / 3600) * 1000 = (N * 3600 / 625 / Tsec) * 1000

Turned off all home appliances except the computer. It turned out in idle mode with C "n" Q on (Vcpu \u003d 1.1 235x5), it turned out 10 revolutions in 700 seconds. When you boot your computer S&M 100% (235x9) 10 revolutions in 400 seconds.

The formula yields the power consumption in idle P ~ 82 W, and at 100% load ~ 144 W.
Not so much. Apparently passport figures are given with a margin. I'll overclock - I'll measure again.

Measured how much the air temperature rises as it passes through my computer.

Air is sucked into the case only through the bottom of the front panel, it is ejected only through the PSU. All other slots on the body are sealed with paper tape.

Only one 120mm fan on the bottom of the PSU works for exhaustat 600 rpm (in the air duct from the CPU to the PSU). The temperature in front of the front panel is 23 ºС.

CPU ~ 0, C ’ n ’ Q is on, Vcpu \u003d 1.08v, 235x5 \u003d 1170 MHz), ΔΤ \u003d 11 ºС.

Based on these figures, you can evaluate the real fan performance at 600 rpm (according to the well-known formula): V=1.75*P/ΔΤ=1.75*82/11~13 CFM . Almost 2 times lower than passport data. Apparently, the decrease in performance is due to the resistance to pressure in the case and due to the turns and narrowing of the channel through which air flows into the PSU. After all, the cross section of the jet in a 120mm fan is 113 sq.cm, and the hole on back wall PSU ~ 60 sq.cm (from removed 80mm fan). I'll have to try to increase it. At the same time, turn the board in the power supply unit with radiators closer to the exhaust hole.

The main other: the performance of one fan 13 CFM at 600 rpm, it is enough to remove heat from the system even when the processor is fully loaded. With a heat dissipation of 144 W, the outlet air must be heated by more thanΔΤ = 1.75 * 144 / 13 = 19 ºС. And if during overclocking the heat release increases to 200W, the heating should be no more than 27 ºС. Those. at an inlet air temperature of 25 ºС, the output air temperature will not exceed 52 ºС, which satisfies temperature requirements for any computer components.

You are on the right path, comrades!

… To Blood makes up about 7 percent of a person's weight. If a person weighs 70 kilograms, then there are about 5 liters of blood in his body.

… D The length of the capillaries of the human body, stretched into one thread, is approximately 100 thousand kilometers. This is more than 10 times the distance from Moscow to Vladivostok.

… H That is, all blood simultaneously circulates through the vascular system. Part of it accumulates in the liver, spleen, bone marrow, forming a kind of "depot", from where it periodically enters the general channel. Blood transfusion, which is done in case of acute blood loss, brings an effect not only in itself: it helps to use the reserves of these natural storerooms of the body.

… D blood pressure in the vessels is different. In the arteries, it is 80-120 mmHg, in the veins - 50-100 mmHg. In the capillaries, the blood pressure is approximately 20 mm Hg.

… D To maintain a constant number of blood cells, it is necessary that the human body receives a "replenishment" daily - more than 300 billion erythrocytes and more than 5 billion leukocytes.

… H and one organ of the human body is not as industrious as the heart.

Here is how his work is expressed in numbers. The heart makes an average of 70 beats per minute, over 100 thousand per day, 35.6 million per year, and 2 billion 200 million beats per 60 years (including life expectancy). With each contraction, the heart pushes out about 60 cubic centimeters of blood; in a minute it will be about 4 liters, in a day - 6 tons, in a year - 2200 tons, in 60 years - 130 thousand tons. To transport this amount of blood in 50-ton tankers, 2600 such tanks would be required.

… E If the force of heart contractions could be used to lift weights, then in 20 days the heart would lift a person to the top of the Caucasus Range - Elbrus.

… H The highest body temperature that a person can still withstand should be considered 44 - 44.5 degrees. In the medical literature, facts are reported that some managed to survive even 45 degrees. But such cases are extremely rare.

… R different parts of our body have different temperature. Inside the liver, it stays at 36-38 degrees, in the mouth it is about 37 degrees, and on the skin of the toes and hands it fluctuates between 26 and 32 degrees.

… And It is interesting to note that if the rise in body temperature is often accompanied by a feeling of chills, cold, then the freezing person falls into oblivion, during which it seems to him that he found himself in a very heated room, in a hot desert, working in a hot shop, etc. e. In a semi-conscious state, the freezing person throws off his boots, outerwear and even underwear. There was a case when a frozen man, found naked, became the reason for initiating a criminal case on robbery and murder. But the investigator and the judges soon established that the frozen man undressed himself.

…To When in the cold we begin to shiver from the cold, this means that our body, like an automatic relay, turns on protective "devices" that increase body temperature. Typically, muscles use from 20 to 40 percent of the chemical energy of food molecules, such as glucose, for their work. The rest of the energy is converted into heat and is partially used to maintain body temperature. If we do not produce muscle contraction in the cold, then the heat generated in the body becomes insufficient to warm us. That's when the muscles themselves begin to contract involuntarily - to tremble, and the heat generated during this trembling restores and maintains normal body temperature.

… E If our body, instead of skin, were covered with a case impervious to heat, similar to a thermos, then in an hour the body temperature would rise by about one and a half degrees, and after forty hours it would reach the boiling point. An adult person, without even doing any work, emits as much heat as a 50-watt light bulb.

… T The heat emitted by a person per day, even at rest, would be enough to heat about three tons of water by one degree or boil two buckets of water.

… AT The human lung contains about three million pulmonary vesicles. If these bubbles were expanded, they would cover an area of ​​one hundred square meters.

... Every second, two new inhabitants appear on the planet. ... Of all the months, most of all newborns “love” January, which accounts for a tenth of all births during the year, and March, which falls on an eleventh of the annual number of births. ... The birth of twins occurs approximately in every 85 births. Triplets are born much less often - one case in 7000 ...

… With each breath, a person does significant work. If it could be used, then the energy would be enough to lift a load weighing up to 500 kilograms to the height of the second floor in one night. ... It has been established that the tip of the tongue has the greatest sensitivity. This is followed by the palmar surface of the fingers, the tip of the nose, the middle of the palm and, finally, the midline of the neck and ...

… Eyes never get cold. This is because they do not have "cold points" - nerve endings that are sensitive to cold. On the contrary, there are a lot of “cold points” in the tips of the fingers, toes, the tip of the nose, in the lumbar region, so these places feel the cold most of all. ... The famous American philosopher and mathematician Charles Sanders (1839 - 1914) is so good ...

… For 70 years of life, a person drinks and receives over 60 thousand liters of water with food, eats more than 11 thousand kilograms of carbohydrates, about 2.5 thousand kilograms of proteins and almost the same amount of fat. ... The phrase on the monument that adorned the grave of a 112-year-old man in ancient rome: "He ate and drank in moderation." … The ancient Greeks highly valued the good…

… green tea meet you wherever you go in China. For the Chinese, it replaces much more strong drinks. Neither sugar, nor lemon, nor milk is ever added to tea. There are a great variety of green tea varieties in China; some of them are mixed with jasmine petals for aroma. … Tibetans drink brick tea from flat wooden…

… According to preserved handwritten information, coffee was known in Arabia and Persia as early as 875. … About coffee tree penetrated into Europe at the end of the 16th century, and in 1573 the German doctor Rauwolf reported about a coffee house he saw in Aleppo. The first bags of coffee were brought to Europe from Turkey in 1615 by ships…

... In ancient India, abstinence from alcohol was considered mandatory for all classes. People caught drunk were given molten silver, lead or copper to drink. … Charlemagne dealt with drunkards in the following way: the first time they were punished in a closed room, then in public. If these measures did not help, drunkards were executed. ... In England at the beginning of the last century ...

The human body is constantly generating heat. And this process does not depend on our desire, the amount of food eaten or the state of health. And if in cool weather people themselves warm themselves with this warmth, then in summer or indoors this heat, one might say, is wasted. But recently, the first experiments on the use of this thermal energy began.

It is known that the body of an adult healthy person with normal temperature at rest, it generates heat in the equivalent of 60 W / h. If he is engaged in light physical work, for example, walking, then this value increases to 100-120 W / h. And athletes during intensive training warm up the surrounding air by 800-900 W / h.

A fairly small part of this heat is used to heat the body and its organs directly - no more than 50%. The rest simply dissipates into the atmosphere, regardless of our desire. The most rational use of this heat is heating air gap under winter clothes or a blanket. In other cases, we can talk about useless consumption.

The surface of the human body generates heat unevenly and it is very problematic to connect heat exchangers to it. And the efficiency of such a system will leave much to be desired, since a person cannot do intensive physical work all the time. Until recently, to take advantage of the warmth of a person for economic needs was problematic.

Stockholm experiment

At present, the central building of the Stockholm railway station has been turned into a kind of experimental ground. Air conditioners were removed from the main halls, the walls were equipped with a layer of thermal insulation, and door and window openings were made less breathable. Heat exchangers were installed inside the ventilation system and connected to the heat supply system of the neighboring building.

Every day, about 250 thousand people pass through the station building, which emit up to 25 MW of thermal energy. Most of it in the form of heated air is collected in the ventilation and through heat exchangers the energy is transferred to heat water in the heating system of another building. Cooled down, but saturated with CO 2 air enters the outside, and in its place fresh and still cool air is pumped in from the street.

Calculating the efficiency of such a system is problematic, but according to rough estimates, it can save up to 25% of the energy used to heat the building. At the same time, the construction of such a heater does not require special investments, and it can be installed in the most different places crowds of people - in the subway, in supermarkets, in banks, etc.

Comments:

Power is measured in watts, and energy is measured in watts times a unit of time, such as an hour. Thus, a 100 W lamp burning for two hours dissipates 200 Wh of energy. The article features a non-existent unit W / h. Power divided by time has no physical sense.
The meaning of the phrase “Every day about 250 thousand people pass through the station building, which emit up to 25 MW of thermal energy”, is not clear. Megawatts do not measure energy, but power. If we mean the energy released per day, then it should be measured in MWh.

In physics, sometimes a semi-scientific “method of dimensions” is used to solve problems, when, knowing the dimension of the desired value, we can guess what to divide, add, multiply into to get the correct answer. I decided to take the dimension "energy" and compare "apples with bananas", namely, a person as energy system with other systems.

How is energy measured?

Disclaimer: all calculations may not be exact and the main purpose is to show the order of numbers.

Man is a consumer of energy. 2 kWh, 100 W

An average person consumes about 2000 kcal per day, which gives about 2 kWh or about 100 watts, average power. You can imagine that a person eats like one big 100-watt incandescent bulb.

Human energy consumption is relatively small compared to the devices that surround us. We can say that man has made a technical revolution. A person takes in less energy than he uses “for himself” even at home (the average calculation is more than 100 kWh per month).

Man is a computer. 30 W

It is widely estimated that the brain eats from 200 to 1000 kcal ( stressful situations), that is, from 20%-40% of energy, which gives an average power estimate of 30 watts.

The brain is an extremely efficient system. Yes, modern laptops perform operations much better than us and the average power is about 30 watts, and phones are generally 0.5-1 watts. But modern video cards consume an average of 250 W and still cannot be compared with the brain in terms of speed and accuracy of processing visual information. So, a person is a very good processor, though only for specific tasks.

Man is a battery. 10 kWh

They say that a person can not eat for 3-7 days. It is clear that without eating, a person will begin to consume less energy for internal and external needs. It can be assumed that having eaten a double daily allowance, a person will be active for 2 days (if water is available), which gives a rough estimate of 10 kWh.

If we calculate the energy intensity of a person, then we can get extremely different numbers, the weight of people who can live Nth quantity days and produce some useful work, varies greatly from 50 kg - 150 kg. Most likely, the average energy intensity is 0.1 kWh/kg, which is not so good and not so bad. We are between gasoline (10 kWh/kg) and Liion (0.1 kWh/kg), closer to batteries.

Man is a consumer of solar energy. 1-2 solar panels

Today's the solar panel gives about 300 watts at the peak, in temperate latitudes the average power factor is up to 20% (the sun shines only during the day and weakly). We know that a person is short-lived, but still a battery, so on average 2 panels are enough for a person to eat only the sun.

If we discard conventions and make small breakthroughs in technology (the use of expensive elements allows us to achieve up to 40% efficiency in panels), it will be enough for a person to wear “solar clothes” in order to receive all the necessary energy.

Man is a heater

I will quote: at rest, the human body produces 80 watts of heat, and at the same time loses 10 watts due to breathing, 30 watts of thermal radiation, 20 watts of heat conduction and convection, 20 watts of moisture evaporation.

It turns out that a person is an extremely “weak” heater. Household heaters consume 1 kW each and they cover the heating needs only partially. Hot water and space heating are by far the largest energy consumption household. Here is my annual schedule:

Movement (transport, fuel): 8,000 kWh per year.
- Electricity: 2,500 kWh per year.
- Water heating and heating: 30,000 kWh per year.

It turns out for the average daily heating of water and heating takes up to 100 kWh per day, which is 50 times more than a person consumes in principle.

A person is a means of transportation (car, pedestrian, bicycle)

Man as an active living being can move in space. Let's say a person can move 30 km in a day on foot and 120 km in a day on a bicycle. These are not the maximum values, of course, athletes run up to 100 km and drive up to 1000 km per day.

Let's try to compare a person as effective system human movement.

A car with an internal combustion engine spends an average of 5 liters per 100 km, 1 liter = 10 kWh, which gives 500 Wh per km
- Electric car - 150-200 Wh per km
- Pedestrian - 2 kWh divided by 10-50 km, 50-200 Wh per km
- Slow/small electric car - 50-100 Wh per km
- Electric bike - 10 Wh/km(average speed 10-15 mph)
- Cyclist - 2 kWh divided by 100-1000 km, 2-20 Wh per km

Know more interesting coincidences - write in the comments.
Thank you for your attention.

With proper PC design, one of milestones this work is to calculate the computer cooling system and thermal regime its nodes. And not only when designing in design organizations, but also when modifying them, overclocking and modding at home. True, in the latter case, these calculations may have less accuracy. I sometimes get the feeling that the Chinese corps are calculated with even less accuracy, if at all. And if you need a computer that works at any temperature, when overclocking its components or has a low noise level, you need to be able to calculate its heat release and make at least an approximate calculation of its heat transfer, but with a mandatory subsequent check of efficiency after the design is completed. I draw your attention to the fact that accurate calculations require a lot of work and experience.

Introduction.

There are several approaches to calculating heat dissipation in a computer case, but here I want to focus on four. Each of them has its own advantages and disadvantages.

According to the passport values ​​of the power consumed by the nodes,

Advantage: accessibility, simplicity.
Disadvantages: high error and, as a result, excessive requirements for the cooling system.

Just go to the site that provides a service for calculating heat dissipation (power consumption), select the necessary nodes and, hoping for the modernity of their database and the correctness of the values ​​laid down, apply their results.

Advantage: no need to search for data, they must be present in the databases of the offered services.
Disadvantages: databases do not keep up with node manufacturers, they often contain unreliable data.
In the article we will not consider it, for its implementation you only need to know the address of the resource and the composition of the nodes of your computer and the time.

According to the power consumed by the nodes, taking into account the heat release coefficient and the typical load of the nodes,

Advantage: higher accuracy (optimality).
Disadvantages: a large amount of information or experience is required, knowledge of the characteristics of the nodes, PC operating modes.

According to the results of experimental measurements by power consumption devices and computer tests. Testing can be performed at least extreme values, heat dissipation at rest and at full load

Advantage: high accuracy of the value for each typical operating mode.
Disadvantages: the need for special studies and measurements.

Calculation of the power consumed by the PC, according to the passport values ​​​​of the power consumption of the nodes

When the question “How much heat does my computer generate?” comes up, the first thing we try to do is find data on the heat dissipation of the nodes that are in your PC case. But there is no such data anywhere. The maximum that we find is the currents consumed by the nodes in the power circuits 3.3; 5; 12 V. And even then not always.

These consumption current values ​​\u200b\u200bmost often have peak values ​​\u200b\u200band are intended rather for choosing a power supply in order to exclude its current overload.

Since all devices inside the computer are powered by direct current, there is no problem to determine the peak (precisely peak) power consumption of your node. For this, the sum of the powers consumed by each line is simply determined by multiplying the current and voltage consumed by the circuit (I draw your attention, no conversion factors are applied - direct current.).

P sum = P 5v + P 12v = I 5v *U 5v + I 12v *U 12v

As you understand, this is a very rough estimate, which in real life almost never executed, because all the nodes of the computer do not work simultaneously in peak mode. The operating system works with PC nodes according to certain algorithms. Information is read - processed - recorded - some part of it is displayed on the means of control. These operations are performed on data packets.

On the Internet, there are many estimates of exactly the value peak power consumption taken from the characteristics of the nodes.

Those calculations that were made 2-3 years ago, in principle, do not correspond to the current situation. Because over the years, manufacturers have upgraded their nodes, which has led to a decrease in the power they consume.

The latest data is shown in Table 1.

No. pp	Knot	Power consumption per node, W	Explanations
1	Processor (CPU)	42 - 135	See your processor specification for more details.
2	Motherboard	15 - 100	More precisely, see publications or perform the calculation yourself (depending on its specification)
3	video card	Up to 65	When powered from the bus, see the documentation for more details
		Up to 140	With a separate power supply, see the documentation for more details
4	RAM	3 - 15	Depends on capacitance and operating frequency, see documentation for more details
5	Hard disk, HDD	10 - 45
6	CD/DVD-RW	10 – 30	Depends on the mode of operation, more precisely see the specification
7	FDD	5 – 10	Depends on the mode of operation, more precisely see the specification
8	Sound card	3 - 10	Depends on the mode of operation, more precisely see the specification
9	Fan	1 - 4,5	See specification for more details.
10	LAN card/ built-in	3 - 5	See specification for more details.
11	USB 2/USB 3 port	2,5/5 (according to some reports more than 10 watts per USB3 port)	Per connected port
12	COM, LPT, GAME ports	< 2	Per connected port
13	Built-in sound card	< 5	When using passive speakers
14	Power Supply	P cons. max + 30%	Selected after consumption calculation

Table 1.

We see the data has a very wide spread, it is determined by the specific model of your node. Units from various manufacturers, especially those produced in different time have a wide range of power consumption. In principle, you can do the calculation yourself.

The calculation of the power consumed by the PC is carried out in several stages.

Collecting information about the power consumed by the node,

Calculation of the total power consumption and the choice of PSU,

Calculation of the total consumption of the PC (including the power supply).

An integral part of the calculation of heat dissipation is the calculation of the power consumed by the computer. From which the power of the power supply is determined, is selected specific model, after which its heat dissipation is estimated. Therefore, performing a thermal calculation, you first have to collect data on the power consumed by the computer nodes.

But so far, even the power consumption is not always given by the manufacturers of computer components, sometimes the value of the supply voltage and the current consumption for a given voltage are given on the rating plate. As mentioned above, at direct current, which is used to power computer components, the product of the supply voltage and the current consumed by this voltage indicates the power consumption.

Based on the total power consumption (taking it as the heat dissipation power), you can perform a preliminary or approximate calculation of the cooling system. This calculation will provide rather excessive cooling of your PC, which, under conditions of high load and, accordingly, maximum heat dissipation, gives some approximation to real heat dissipation and ensures normal cooling. But when the PC is used on normal (not resource-intensive) applications, the cooling system calculated in this way is clearly redundant, and ensuring the normal functioning of the PC nodes, creates inconvenience for the user due to advanced level noise.

First of all, you should know that the power consumption and heat dissipation of nodes have a direct relationship.

The heat dissipation power of electronic assemblies is not equal to the power consumed, but they are interconnected through the node's power loss factor.

There are many publications on how to perform this calculation, there are special sites on the Internet for this calculation. But there are still questions about its implementation.

And because not only is the heat dissipation power difficult to find from the manufacturer, but even the power consumed by the node of interest to us is not always known. Perhaps they are simply afraid to give them due to the fact that their value is not constant in the process of work and significantly depends on the mode of operation. The difference can reach ten times and sometimes even more.

They don't seem to want to overload users with "unnecessary" information. And I have not yet found data for manufacturers.

At read the heat dissipation coefficient.

Efficiency.

The heat dissipation power of conventional physical devices (fans, electric and mechanical motors) is determined through the concept of efficiency. Which is defined as the ratio of useful power (the power expended to perform useful work) to the power loss (the power that goes to overcome friction, heat, ...). But the concept of efficiency is unacceptable for electronic components. Them useful work not measured in watts or joules. The efficiency of their work determines rather the performance, which is ambiguously related to the power consumed. It is more correct to call it the "Heat Release Coefficient".

Heat release coefficient.

For PC nodes - chips, microcircuits and others, the well-known concept of efficiency is not suitable, because it is often impossible to estimate the useful power. To do this, it is better to use the power loss factor, which characterizes the proportion of power consumed by the node that turns into heat.

K t \u003d P heat / P cons

P heat \u003d P cons * K t

Here: P con - power consumed by the node from the power source, P warm - heat dissipation power of the node, K t - heat release coefficient.

The share of power consumption output outside the chip in the form of the information we need is insignificant, which makes it possible, in rough calculations, to equate P heat and P cons.

The heat dissipation power of modern chips is determined by their load and the nature of their work.

A feature of the operation of modern processor chips and other microcircuits is that they TDP( heat dissipation power) manufacturers obtain by simply multiplying the chip's supply voltage by its consumption current. For the reasons stated above, this value can be used to calculate their heat dissipation. But, as mentioned above, it significantly depends on the operating mode of the chip.

Below, in table 2, guide values ​​are givenTo t for various nodes PC.

No. pp	Knot	K t	Explanations
1	Processor, chip	0, 95 - 0,99	Power tends to increase
2	inverter (Built-in power supply)	0,72 - 0,89	Depends on the circuit design and the applied element base, with increasing power K T grows
3	Hard disk, HDD	0,95	Depends on the speed of the drive, more speed - more heat dissipation
4	CD/DVD-RW	0,8 - 0,95
5	FDD	0,8 - 0,95	More on standby
6	Sound card	0,5 - 0,85	Greater value for small P out
7	Fan	0,7 - 0,9	Axial fan
		0,15 - 0,7	Centrifugal fan
8	Power Supply	0,78 - 0,85	Depends on the circuit design and the applied element base, with increasing power K T grows

Table 2.

K t depends on the operating mode of the node or its load.

Motherboard as a heat source.

For most, it is not a secret that the motherboard itself, while ensuring the operation of the nodes installed on it, consumes electricity and generates heat. Heat is emitted by the north and south bridges of the chipset, power supplies for computer nodes, and simply components located on it electronic circuits. Moreover, this heat dissipation is the greater the more productive your computer. And even during operation, heat dissipation varies depending on the workload of its nodes.

The northbridge chip, which provides the processor with buses, has the highest heat dissipation. And often work with memory modules (in some models of modern processors, they perform this function themselves). Therefore, their heat dissipation power can reach from 20 to 30 watts. The manufacturer usually does not list their heat dissipation, as in general the total heat dissipation of the motherboard.

An indirect sign of high heat dissipation is the presence of an inverter to power it in close proximity to it and an enhanced cooling system (fan, heat pipes). Remember, power and cooling must provide normal work chipset for maximum performance.

Now, one phase of such a power supply accounts for up to 35 W of output power. The power supply phase consists of a pair of MOSFETs, an inductor, and one or more oxide capacitors.

Modern high-speed memory modules also have a fairly large heat dissipation. An indirect sign of this is the presence of a separate power supply and the presence of an additional heat sink (metal plates) installed on the memory chips. The power of heat dissipation of memory modules depends on its capacity and operating frequency. It can reach 10 - 15 watts per module (or 1.5 - 2.5 watts per memory chip located on the module, depending on performance). The memory power supply dissipates 2 to 3 watts of power per memory module.

CPU.

Modern processors have a power consumption of up to 125 and even 150 W (the current consumption reaches 100 A), so they are powered by a separate power source containing up to 24 phases (branches) operating per load. The power dissipated by the processor power supply for such processors reaches 25 - 30 watts. The documentation for the processor often indicates the parameter TDP (thermal design power) characterizing the heat dissipation of the processor

Video card.

Modern motherboards do not have additional power supplies for video cards. They are located on the video cards themselves, since their power significantly depends on the operating mode and the graphics processors used. Video cards with additional power sources (inverters) are powered through an additional +12 V PSU outlet.

Element base of the motherboard as a heat source.

Due to the growth in the number external devices, the number of external ports that can be used to connect external devices that do not have their own power sources (for example, external HDDs on USB ports) is also growing. Up to 0.5 A per USB port, and there can be up to 12 such ports. Therefore, additional power supplies are now often installed on the motherboard to service them.

We must not forget that all the radio elements installed on the system board emit heat, to one degree or another. These are specialized chips, resistors, diodes and even capacitors. Why even? Because it is believed that no power is released on capacitors operating on direct current (except for the insignificant power caused by leakage currents). But there is no pure DC in a real motherboard - power supplies are switching, loads are dynamic and always present alternating currents in their chains. And then heat begins to be released, the power of which depends on the quality of the capacitors (ESR value) and the magnitude and frequency of these currents (their harmonics). And the number of phases of the inverter power supply of the processor has reached 24, and there are no prerequisites for their reduction on high-quality motherboards.

The total heat dissipation power of the system board (only one of it!) can reach a peak of 100W.

Heat dissipation of power supplies integrated on the system board.

The fact is that now, with the increase in power consumed by computer nodes (video card, processor, memory modules, chip sets of the north and south bridges), they are powered from special power supplies located on the motherboard. These sources represent failure of multi-phase (from 1 to 12 phases) inverters operating from a source of 5 - 12V and supplying consumers with a given current (10 - 100 A) at an output voltage of 1 - 3V. All these sources have an efficiency of about 72 - 89%, depending on the element base used in them. Various manufacturers use different methods removal of generated heat. From simple heat dissipation to the motherboard by soldering MOSFET key transistors to the printed conductor on the board, to special heat pipe coolers using special fans.

The built-in power supply is a conventional inverter, with multi-phase switching it is several (the number corresponds to the number of phases) synchronized and phased inverters operating on one load.

An example of estimating heat dissipation in the chain "processor - multi-phase inverter - power supply".

The calculation of the heat dissipation power in the chain "processor - multi-phase inverter - power supply" is performed based on the power of the end consumer in the "processor" chain.

The fact is that now, with the increase in power consumed by computer nodes (video card, processor, memory modules, chip sets of the north and south bridges), they are powered from special power supplies located on the motherboard. These sources represent failure of multi-phase (from 1 to 12 phases) inverters operating from a source of 5 - 12V and supplying consumers with a given current (10 - 100 A) at an output voltage of 1 - 3V. All these sources have an efficiency of about 72 - 89%, depending on the element base used in them.
The built-in power supply is a conventional inverter, with multi-phase switching it is several (the number corresponds to the number of phases) synchronized and phased inverters operating on one load.
Different manufacturers use different methods for dissipating the generated heat. From simple heat dissipation to the motherboard by soldering MOSFET key transistors to the printed conductor on the board, to special heat pipe coolers using special fans.
Approximate calculation of heat dissipation in the power chain.

Let's take a look at this chain.

The result of the consideration will be the answer to the question: "What power is allocated to the power supply of the device located on the system board?"

AT Let's take the AMD Phenom™ II X4 3200 processor as an example, which has a peak power consumption (TDP) of 125W. This, as already mentioned above, with a fairly high accuracy of its heat release.

The multi-phase inverter from which the above processor is powered, practically regardless of the number of phases, at efficiency = 78% (typically), generates heat 27.5 W peak.

Total total heat dissipation in the power circuit of the AMD Phenom™ II X4 3200 processor and its power supply (inverter) at the peak reaches 152.5 W.

The share of heat dissipation in the PSU attributable to this processor will be (taking into account the efficiency of the PSU) more than 180 W at the peak of the processor load.

To calculate the share of the power (current) of the supply per given circuit for the PSU, the total power is used - 152.5 W. To translate given power You need to know what voltage this circuit is powered by. And it depends not so much on the processor and power supply unit (PSU), but on the design of the motherboard. If the power is supplied from a voltage of 12V, it is calculated from the total power consumed in this circuit, converting this power into current and we get, at a circuit voltage of 12V, the total current consumed from the PSU for the processor power circuit is - 12.7A.

Checking the efficiency of the cooling system of the computer you have assembled.

As mentioned above, the verification of the correctness of your heat dissipation calculations and the choice of case design will be the verification of your calculations and the effectiveness of the cooling system you have chosen.

The check consists in monitoring the temperature of the nodes (main) of your computer. It must not exceed maximum temperature defined by their manufacturers. And even have some margin (in my opinion, about 20 ° C). this reserve will ensure the smooth operation of your computer in critical conditions. It may be dusty air filters, new more resource-intensive applications that you have installed on your PC and even just summer heat.

Conclusion.

As you understand, with modern heat dissipation of nodes, the calculation of the power consumed by your computer, during its modding and self assembly must always be done. It is needed to select a power supply, one of critical devices computer, and ultimately an estimate of the total power consumed by your computer.

The received power consumption can be used as the maximum possible heat dissipation power, taking into account the fact that the heat dissipation power is always lower than the consumed power.

If you have enough experience to determine the range of tasks performed by your computer, load its components and evaluate their heat dissipation during operation, then you can estimate its heat dissipation with an accuracy higher than that given by the calculation of power consumption.

But it is not yet possible, due to the wide range of components and their manufacturers, to calculate the heat dissipation power of a computer with high accuracy. This is possible only when modeling a specific constructive solution and a wide range of measurements of its characteristics, including heat release and heat transfer modes. In production conditions, this procedure is called a set of factory tests.

The output for a moder or faucet could be:

power consumption measurement,

power consumption calculation,

In the latter case, we get excess heat, respectively, excess air exchange. To optimize it, I recommend using electronic fan speed controllers. This will remove the redundancy of air exchange and reduce the noise level of the ventilation system.

The use of cooling fan speed controllers with rotation speed and temperature monitoring, in addition to the direct function of regulating the air flow through cooled objects, also allows you to create temperature monitoring at critical points of your computer.

P.S.

And lastly, since it is difficult to ensure stable operation of cooling systems in such a wide range of heat dissipation, I would recommend permanently introducing a monitoring and fan control controller into your computer configuration. This will provide approximately 3x regulation of the air flow through the cooled units and monitoring of temperatures at critical points.

Literature.

Power measurement, G.P. Manin, M-L, Energy, 1965

Measurement of computer power consumption, Oleg Artamonov, http://www.fcenter.ru/online.shtml?articles/hardware/tower/6484 , 04/28/2003

October 2008