Watt calculator for power supply online. How to calculate the power of a computer power supply? Here is a sample consumption list
A power supply is a PC component that converts network 220 V into the 3.3-12 V required for various devices. And, alas, many people relate to the choice of a power supply ... nothing - they just take it for rent from buying other components, often right away along with the hull. However, if you are assembling something more powerful than a multimedia computer, then you should not do this - a bad power supply can easily disable expensive processors or video cards, and so that later it would not be like in the saying “the miser pays twice” - it is better to buy a good PSU right away.
Theory
First, let's figure out what voltage the power supply gives. These are the 3.3, 5 and 12 volt lines:
- +3.3 V - designed to power the output stages of the system logic (and generally power the motherboard and RAM).
- +5 V - powers the logic of almost all PCI and IDE devices (including SATA devices).
- +12 V is the busiest line, it powers the processor and video card.
But the 12 V line is very busy - both the processor (50-150 W) and the video card (up to 300 W) are powered by it, so the most important thing in the power supply is how many watts it can deliver through the 12 V line (and this the figure by the way is usually close in the total power of the power supply).
The second thing you need to pay attention to is the power supply connectors - so that it doesn’t happen that the video card needs a couple of 6 pins, and the power supply has only one for 8 pins. The main power supply (24 pin) is on all power supplies, you can ignore this. Additional CPU power is presented in the form of 4, 8 or 2 x 8 pins - it depends on the power of the processor and the motherboard, respectively, make sure that the power supply has a cable with the required number of pins (important - 8 pins for a video card and a processor are different, do not try swap them!)
Next is the additional power supply for the video card. Some low-end solutions (up to the GTX 1050 Ti or RX 460) can be powered by a PCI-E slot (75 W) and do not need additional power. However, more powerful solutions may require from 6 pins to 2 x 8 pins - make sure that the power supply has them (for some power supplies, the pins may look like 6 + 2 pins - this is normal, if you need 6 pins - then connect the main part with 6 pins, if you need 8 - add 2 more on a separate cable).
Peripherals and drives are powered either through a SATA connector or through Molex - there are no splits into pins, just make sure that the power supply has as many necessary connectors as you have peripherals. In some cases, if the power supply does not have enough pins to power the video card, you can buy a Molex - 6 pin adapter. However, in modern PSUs, such a problem is quite rare, and Molex themselves have almost disappeared from the market.
Power supply form factors - they are selected either for the case, or, conversely, if you have chosen a good PSU of a certain form factor, then you already select the case for it and the motherboard. The most common standard is ATX, which is what you'll most likely see. However, there are more compact SFX, TFX and CFX - they are suitable for those who want to create a very compact system.
The efficiency of a power supply unit is the ratio of useful work to the energy expended. In the case of power supplies, their efficiency can be recognized by the 80 Plus certificate - from Bronze to Platinum: for the former it is 85% at 50% load, for the latter it is already 94%. There is an opinion that a 500W 80 Plus Bronze certified power supply can actually deliver 500 x 0.85 = 425W. This is not so - the unit will be able to give 500 watts, it will simply take 500 x (1 / 0.85) = 588 watts from the network. That is, the better the certificate - the less you have to pay for electricity and no more, and given that the difference in price between Bronze and Platinum can be up to 50% - there is not much point in overpaying for the latter, saving on electricity will pay off oh how not soon. On the other hand, most of the expensive power supplies have at least a Gold certificate, that is, you will be “forced” to save electricity. 
Power Factor Correction (PFC)
Modern blocks are becoming more powerful, and the wires in the sockets do not change. This leads to the appearance of impulse noise - the power supply is also not a light bulb and, like the processor, consumes energy in impulses. The stronger and more uneven the load on the unit, the more interference it will release into the power grid. To combat this phenomenon, PFC has been developed.
This is a powerful inductor installed after the rectifier before the filter capacitors. The first thing it does is limit the charge current of the aforementioned filters. When a unit without PFC is connected to the network, a characteristic click is very often heard - the current consumed in the first milliseconds can be several times higher than the passport one and this leads to sparking in the switch. During the operation of the computer, the PFC module dampens the same impulses from the charge of various capacitors inside the computer and the spin-up of hard drive motors.
There are two versions of the modules - passive and active. The second is distinguished by the presence of a control circuit associated with the secondary (low-voltage) cascade of the power supply. This allows you to quickly respond to interference and smooth them out better. Also, since there are a lot of powerful capacitors in the PFC circuit, an active PFC can “save” the computer from shutting down if electricity disappears for a fraction of a second.
Calculation of the required power supply power
Now that the theory is over, let's move on to practice. First you need to calculate how much power all PC components will consume. The easiest way to do this is to use a special calculator - I recommend this one. You drive in your processor, video card, RAM, disks, number of coolers, how many hours a day you use a PC, etc., and in the end you get this chart (I chose the option with i7-7700K + GTX 1080 Ti): 
As you can see, under load, such a system consumes 480 watts. On the 3.3 and 5 V lines, as I said, the load is small - only 80 W, even the simplest PSU will give so much. But for 12 V lines, the load is already 400 watts. Of course, you should not take the power supply back to back - 500 watts. He, of course, will cope, but, firstly, in the future, if you want to upgrade your computer, the PSU can become a bottleneck, and secondly, at 100% load, the power supplies are very noisy. So it’s worth making a reserve of at least 100-150 W and taking power supplies starting from 650 W (they usually have 12 V lines output from 550 W).
But here there are several nuances at once:
- You should not save and take a 650 W PSU built into the case: they all go without PFC, that is, one power surge - and at best you go for a new PSU, and at worst - for other components (up to the processor and video card) . Further, the fact that 650 W is written on them does not mean that they will be able to give so much - a voltage that differs from the nominal value by no more than 5% (and even better - 3%) is considered normal, that is, if the power supply unit gives 12 There is less than 11.6 V in the line - you should not take it. Alas, in noname PSUs built into the case, drawdowns at 100% load can be as high as 10%, and what's even worse - they can produce a significantly higher voltage, which may well kill the motherboard. So look for a PFC with active PFC and 80 Plus Bronze certification or better to ensure you have good components inside.
- It may be written on the box with the video card that it needs a 400-600 W PSU, when it itself barely consumes 100, and the calculator gave me 200 W under load at all - is it necessary to take a 600 W PSU? No, absolutely not. Companies producing video cards are very reinsured, and deliberately overestimate the requirements for the PSU, so that even people with a PSU built into the case are likely to be able to play (because even the simplest 600 W PSU should not sag at a load of 200 W).
- If you are assembling a quiet assembly, then it makes sense to take a PSU one and a half and even 2 times more powerful than what your system actually consumes - at 50% load, such a PSU may not turn on the cooler at all for cooling.
The task of the computer power supply is to turn 220 volts AC into three different DC voltages. The incoming mains voltage constantly fluctuates slightly, and the load on the video card, central processor and other components often “jumps” very strongly. In this case, the power supply is required to constantly and accurately maintain the desired voltage.
The power supply is one of the key components that affect the security of the system as a whole.: if there is any defect, the currents passing through it can damage the components connected to it and even cause a fire. In general, there are plenty of arguments for a serious approach to choosing a high-quality PSU.
A good PSU should operate as efficiently as possible (i.e. with low heat loss). It is also undesirable that its fans are very noisy. And the electrical elements must be completely silent at low load (the noise of the chokes should not be heard).
Power
Depending on the components, computers can consume power from a few watts to several kilowatts. The power supply must be designed to handle the maximum load, and it is desirable to have reserves - only in this case it will work efficiently and quietly.
The optimal PSU power can be calculated by the sum of TDP(thermal package) of the processor and video card, multiplied by 1.5. So, for a Core i5-8600 processor (TDP 65 watts) and an AMD Radeon RX 560 video card (TDP 75 watts), a power supply unit with a capacity of at least 450 watts is suitable. A 450-watt unit would be loaded by about 50%, a 750-watt unit by 30%. For an accurate calculation, use the power supply wattage calculator: bequiet.com/en/psucalculator.
| PSU power | 400 watts | 550 watts | 800+ Watts | |
| CPU | middle class | high class | high class | high class |
| video card | middle class | high class | ||
| Second video card | - | - | - | high class |
| SATA connectors | >8 |
Power supply for office PC
If you are building a simple PC for office tasks, then it is not at all necessary to buy a powerful power supply. Enough and 300 watts. But you still need to have a stock. After all, you can work not only in Word, but also edit graphics and even build 3D models. For these purposes, a 500 W PSU is perfect, you won’t feel much savings when buying a device with a lower return (if you take high-quality ones).
Depending on the components used in them and the cooling system, their price varies from 2,000 to 7,000 rubles. In order for your PC to serve for a long time, we recommend not to save much and opt for a power supply from a well-known brand, for example, Thermaltake TR2 S 500W, which costs about 3,200 rubles.
It has a very quiet cooler, high-quality elastic braided wires, and delivers 75W on the 5V line and 420W on the +12V line.
Efficiency
So, a good power supply provides the maximum possible power consumption of all PC components. In order to be able to evaluate the efficiency of the power supply even before purchase, manufacturers certify them according to the 80 Plus energy saving standard with additional levels of Bronze, Silver, Gold, Platinum and the very rare Titan.
Each power supply generates heat that, in rare models with a passive cooling system, is only removed by a heatsink, requiring precise planning and constant optimal environmental conditions. For users who are extremely sensitive to noise, we recommend a power supply with a hybrid cooling system, such as Corsair RM550x, costing about 8,000 rubles.
Corsair RM550x notable in that its fan only turns on when the load exceeds 40% or the temperature rises. This ensures stable continuous operation under all circumstances. For other users, we recommend conventional PSUs with an active cooling system - for example, be quiet Straight Power 10. Its fan runs almost silently under light load. Noise only appears when full power is required.
Expensive capacitors last longer
The first step to high quality is the choice of well-known manufacturers: be quiet!, Cooler Master, Corsair, Enermax, Thermaltake Xilence and others. As for equipment, when choosing a power supply, you should pay attention to the presence of all the necessary plugs - affordable models often do without a power connector for SATA devices, and some may even comply with the outdated standard.
Also check the exact number of 12V plugs (6-pin or 8-pin) for your graphics card. A modern modular connection technology Cable management allows you to connect only the cables you need to the PSU and not mess up the case.
Expensive capacitors of top PSU models withstand high temperatures (for example, not 85 ° C, but 105 ° C), so they last longer. Manufacturers can anticipate this fact quite accurately. Long-lasting power supplies can be searched among models with a five-year warranty. For example, CoolerMaster G650M, with a power of 650 watts and a cost of about 5,600 rubles.
A photo: manufacturing companies
More recently, I was asking the price in online stores to system units. After weighing all the pros and cons, I came to the conclusion that it is better to buy components separately and freely assemble the system unit on your own and at the same time save a pretty decent amount of money. I have not yet fully decided on the components, but I have already picked up some set of components and I had to make a calculation of the power supply for the computer. Knowing the power consumption parameters of all components, you can approximately calculate the power of the PSU on paper.
What parameters do you need to know in order to calculate the power of the power supply for the system unit? First, you need to know the power consumption of the processor and video card, the physical amount of memory, type and frequency. Secondly, the number, volume and type of drive (hard drive or SSD), as well as the presence and type of drives. In addition, it is important to know the class of the motherboard and its power consumption, as well as the type of cooling system. I listed all the components for an example offhand. After all, different internal components, expansion cards (for example, a TV tuner or a sound card) can be used in a computer configuration, and then it will be necessary to take into account their presence when calculating power consumption.
It is not a problem for a specialist to accurately calculate the consumption of a system unit, but sometimes it is not easy for a novice geek. Therefore, in the calculations you should always take what is called with a margin. Suddenly decide to install a second video card, unless of course the motherboard allows.
If you buy a power supply with insufficient power or make a mistake in the calculations, then due to a lack of power supply to all computer components, it will turn off when the system is fully loaded. You will have to make a return or keep it for yourself. If you are still on your way to becoming a specialist, then I recommend using a specialized power supply power calculator for calculations.
Power consumption calculator to calculate the power of the PSU.
It doesn't matter what you decide to build, upgrade or overclock. A well-balanced home HTPC media server or a modern and powerful gaming computer, or maybe you decide to replace the video card and add a second hard drive. In any case, I recommend that you use an online calculator to calculate the power of the power supply.
Looking ahead, I want to say that with prolonged loads (24/7) of the computer, the power of the PSU begins to fall after a year. This is due to the loss of capacitance of the capacitors and subsequently the PSU weakens. Therefore, be sure to consider how many hours a day the computer will work. Fortunately, this calculator has such a parameter on the “Expert” tab, and on the “Basic” tab, the standard keyboard, mouse and 8 hours of machine use per day are already included in the calculations.
- Motherboard - Motherboard. Several types are available. Desktop is the desktop form factor.
- CPU - Processor. Here you need to choose one of two well-known brands AMD or Intel.
- socket A seat on the motherboard for the processor. Multiple selection is activated after determining the manufacturer of the processor.
- CPU count applies only if the system has more than 1 physical CPU - The number of physical processors. This setting should only be changed if you plan (and are able) to use more than one processor in the system.
- CPU Utilization. How efficiently the cooling system removes heat.
- Memory - Memory. Here, select the desired type and number of memory modules. On the Expert tab, there is an option for FB DIMMs. It is a standard for improving the reliability, speed, and density of the memory subsystem.
- Video Cards - Video card. Select the required type from the drop-down list. The SLI / CF option must be activated if you plan to use multiple video cards
- Storage - Storage. For example, I chose a 10,000 RPM SATA hard drive first, and an SSD second.
- Optical Drives - Optical drive. Recently, I use it quite rarely, but I chose it in the calculator for an example.
After you click on the "Calculate" button, the calculation of the minimum and recommended power of the power supply will be performed. Here you will also receive offers from Amazon, which you can use or use as a guide to buy the model you need in another store. It should be said that in the “Expert” mode, you can also add expansion cards (TV tuner, sound card, controllers, and so on), Bitcoin modules, coolers, and so on.
I recommend paying attention to the PSUs that say 80PLUS Gold, 80PLUS Platinum or 80 PLUS Titanium. This is the 80 PLUS certification and classification of power supply efficiency levels. I would appreciate additions. Bye!
- Processor i 7 8700
- 32 GB G.Skill TRIDENT Z RGB RAM
- Motherboard ASUS PRIME Z370-A II
- Cooling system NZXT Kraken X62
- Vidyaha RTX 2070
- And in the case there are 4 coolers (on dropsy 2)
2019-08-21T17:33:20+00:00
Hello! Please tell me which power supply to take if:
Tell me please.
2017-02-12T16:58:40+00:00
2017-02-12T16:57:27+00:00
Of course you don't have to worry =)
2017-02-10T17:46:08+00:00
Hello, I built a computer a year ago. Video card: Radeon r9 390x PSU: 700w RAM: 2 x 8 GB. Processor: I7 4790 The problem is the following, I just found out that I don’t have 750 PSU, but 700 ... What could be the consequences, because on the box of the video card it says that 750 is recommended. There is no disk drive in the case. Do not consume excess. Should I be worried or not?
2017-01-09T11:01:28+00:00
Hello! Please tell me what kind of PSU is needed for such a system: Proc. i5 6600 Video card MSI gaming X 1070 Mat. board ASUS H170 Pro gaming opera memory 2x8 Kingston Hyper FYRY 3 HDD + 1 SSD 4 cooling fans 140mm + 120mm for the processor It is desirable that there be a reserve for a future update (add turntables, put a reobas or connect a separate sound card) I would like to hear how many watts and which company to take a PSU, because there are a lot of them (corsair, cooler master, zalman, aerokull, etc.) volume of watts and served for a long time) Thanks in advance!
2017-01-01T19:21:46+00:00
I watched a video, it seems that capacitors are better in gold than in bronze. And it seems like if the PSU has an efficiency of 87%, then it cannot be gold. So most likely, the manufacturers are liars :) Happy New Year!
2016-12-27T21:39:02+00:00
As far as I know, Basic, Bronze, Silver, Gold, Platinum is a kind of certification, which is listed in ascending order. Let's say you bought an 850 watt power supply with a basic certification. That is, its efficiency is 85%. Next, we divide 850 by 100% and multiply by 85. It turns out that in fact the power of the purchased power supply will be 688.5 watts. These calculations essentially make it possible to choose the optimal PSU power for the system unit without overpayment. P.S. But based on what you say, it looks more like a marketing ploy.
When buying a computer in a ready-made configuration in a store, many simply do not pay attention to which power supply is installed in the purchased case. And absolutely in vain. After all, the stability and durability of your computer depends on the power supply unit (PSU). Due to a poor-quality or low-power power supply, the computer may spontaneously turn off, give an error, or simply freeze.
Ultimately, this can lead to premature failure of expensive computer components. Therefore, it is recommended to always be interested in which power supply is installed in the system unit. And it is best to choose a power supply yourself and purchase it separately from the case. What are the important aspects to pay attention to when choosing a power supply?
Power supply power
The main parameter of any power supply for a computer is its power. This parameter must be calculated individually for each PC, depending on the power consumption of all system components. The correct calculation of the PSU power is one of the keys to the optimal choice of power supply for your computer. Naturally, in order to calculate how much energy your computer consumes, you need to add up the energy consumption parameters of all its individual nodes - processor, video card, etc.
To do this, you can go to the websites of manufacturers of devices installed in your system unit and find out the power consumption of each system component. After adding up the power consumption of all devices, add about 15 to 25 percent more to the resulting value. This reserve is needed so that the power supply does not work all the time at its maximum power. Thus, the resource of its use will increase.
For automatic power calculation, you only need to select the components of your system unit, including the type of processor, motherboard, RAM, video card, hard drive, additional devices and specify the number of installed components. It is worth noting that not all of these online calculators consider the same and sometimes the difference between the optimal power values in two different calculators can exceed 100 watts.
When choosing a power supply for your PC, pay attention not to its peak power, but to its rated power, that is, to the power that the power supply can reliably provide continuously for a long time. You also need to keep in mind that each of the devices in the system unit is connected to one or more voltage channels, consuming current from them. The power supply produces different voltages on several of these lines. The main load falls on the channels + 12V. It is to these channels that the processor, video card, hard drive and other fundamental components of the computer are connected. Therefore, it is best if there are several such channels in the power supply (+ 12V1, + 12V2, + 12V3, + 12V4, etc.), and their total power will be as large as possible.
Today, almost any home or office system will require a 400-500 W power supply. In general, even for a mediocre or already slightly outdated computer, it is advisable to purchase a medium or powerful power supply. For home and gaming systems, power supplies with a capacity of 450 - 550 watts are suitable. For more advanced gaming systems or computers with two video cards, it is recommended to purchase power supplies with a capacity of 600 - 700 watts. If you are planning to overclock your system unit components, then it is also better to prefer a more powerful power supply.
Types of power supplies for a computer
According to the type of connection of outgoing lines, all power supplies can be divided into three types:
Standard
The standard power supply is a cheap and simple model in which all cables are directly connected to the PSU. This ensures less losses during wired transmission. But in the system unit, there is a mess in the cables, which creates certain obstacles to the free circulation of air and the efficient operation of the cooling system.
Modular
In a modular power supply, cables are connected to it through special connectors, so that the user can connect cables as needed. Using a modular power supply allows you to get rid of unused cables, organize them and, thereby, ensure free air circulation inside the system unit. The disadvantage of modular PSUs is high losses during wired transmission.
hybrid
Such power supplies combine the advantages of standard and modular power supplies. In them, the most important cables are connected directly to the power supply, and additional cables are connected via a modular solution. Thus, both ordering of cables inside the system unit and lower losses during wired transmission are achieved.
Power Factor Correction (PFC)
It is important that the power supply you choose has a so-called power factor correction or PFC (Power Factor Correction) module. The presence of capacitors and coils in the pulse power supply circuit leads to the fact that the network energy is converted into consumed energy non-linearly.
Power factor correction (PFC) is designed to smooth out the resulting ripple and "stretch" it over time. Thus, the power factor is corrected and the operating parameters of the entire power supply circuit are stabilized. The PFC module in the power supply can be passive or active:
Passive PFC
The passive PFC model is a conventional coil (choke) that smooths out voltage ripple. However, the efficiency of the passive module is very low, so it is installed only in inexpensive, budget PSUs.
Active PFC
The active power correction system is an additional board that stabilizes the input voltage and "swallows" short-term voltage dips. The active PFC model provides an almost perfect power factor, filters out mains noise, and generally improves the performance of the power supply. Of course, it is recommended to purchase a PSU with an active power correction system.
Other power supply parameters
The power supply should ideally be as quiet as possible. Fans on the power supply are usually installed both on the side wall and below. Cheap power supplies often do not provide for an automatic fan speed control system. This leads to the fact that the fan in the PSU runs at maximum speed, creating increased noise and often simply overheating. When choosing a power supply, you need to pay attention to the fan or cooler. It is desirable that it be as large as possible, for example, 120x120 mm in size. The larger the cooler, the less noise from its operation.
It is also widely believed that in order to determine the quality of the performance of the power supply, it is necessary to support it in your hands and evaluate its weight. The large weight of the power supply indicates the lack of savings on components, the large size of transformers with radiators and the optimal number of chokes.
However, this point of view already looks outdated, because modern models of power supplies for PCs can have relatively low weight and dimensions with phenomenal power. This is achieved by reducing the size of the power transformer and an improved power supply circuit.
But on the manufacturer of the power supply, of course, you need to pay close attention. Power supplies from trusted and well-known manufacturers, of course, can also be defective, but still their products are not manufactured in artisanal conditions and undergo certain quality control. Among the power supplies from unknown manufacturers, unfortunately, there are many products with disgusting build quality and inconsistency with the declared characteristics. Among the reliable manufacturers are power supplies from FSP, Cooler Master, Antec, OCZ, Zalman, Enermax, Hiper and some others.
Of course, you should not once again save on buying a power supply for your computer. After all, such savings can turn into a need for you to purchase a new motherboard or processor that has failed due to failures in the PSU. Remember that buying a branded and high-quality power supply of the required power is one of the guarantees for the stable operation of your PC.
The correct calculation of the power supply for the computer. calculate the watts of the power supply on the calculator. What are the power supplies and which one to choose? How many watts should a power supply have? What is the voltage in the computer's power supply?
- The top configurations of course Platinum and Titanium, this is the price segment that has exceeded all the norms, let's say, gaming and the most energy-demanding systems. More powerful than the average price segment but lower than the top, the Silver-Gold option will be. For computers with configurations up to the middle price segment, the 80 PLUS Bronze block will be enough, for example, as office ones for PC managers.
- You can calculate the power of the power supply on a calculator and confirm or double-check on several. Below I present to your attention our calculator, on which you need to select the components of your computer and see the total at the very bottom, if your components are not in the list of the calculator, then just select the brand.