Almost every family has a personal computer. When buying it, they primarily look at performance, but no one thinks how much electricity it consumes. The exact numbers depend on the particular system and on when the components were manufactured. Modern devices consume significantly less energy, even with much greater performance. However, gaming systems or older computers, especially if several video cards are used to compensate for the difference with modern models, can consume more than 100 kW per month, and sometimes much more. And this can make you think about saving.
Main consumers
To find out how much electricity the computer consumes, we will figure out which elements are the most demanding. Note that the power for which the power supply is designed is not an indicator. It indicates the maximum at which the manufacturer recommends using it.
The processor, video card and monitor consume the most electricity. The rest of the system requires a modest amount of energy. The consumed value directly depends on the device itself and its performance.
For example, the latest generation i5 processor with 4 cores even consumes up to 140 watts under load, not to mention a modest 50 in idle. But older Intel Quad Core can take more than 200 watts at the time of peak load. And how much electricity a computer with old gaming graphics cards consumes, and it's scary to talk.
The situation is the same with the video card and monitor. True, powerful video cards consume much more power than a processor. Monitor consumption will depend on the brightness of the screen. Modern models require 30 to 50 watts.
Consumption calculation
In order to find out how much electricity a computer consumes, you can calculate based on the characteristics of the system. To do this, you need to know what kind of monitor is used, which processor and video card are installed.
Knowing this data, on the manufacturer’s website you can see how much power is required for components. Of course, the work of the motherboard, RAM, hard drive will also require some energy. This value is very low. For office machines, it can be about 30 watts, and for gaming systems with powerful cooling and an array of memory drives, even up to 200 watts.
Next, we consider two examples, for a budget assembly and a high-performance gaming computer, for greater clarity.
High performance system
To calculate how much electricity a computer consumes, we start with a monitor. Let's say we have a widescreen 34-inch monitor from LG, namely 34UC99-W with a huge resolution. The manufacturer gives information that such a screen requires 50 watts.
Next, consider the video card. For example, we have a modern Geforce GTX 1080 Ti. Or even two. It is worth noting that, thanks to the efforts of the manufacturer and the new process technology, consumption remains very modest. 5 years ago, an average graphics card would have consumed the same amount.
From the characteristics of the device, 250 watts are obtained for one card and 500 watts, respectively, for two. The data is for the card under load. The average consumption when watching a video, easy operation, using the Internet will be about 100 watts for both.
Next is the processor. To calculate how much power the computer consumes, select Intel i9. It requires 140 watts. This is a modest value, since 4-core processors 10 years ago could consume twice as much. The value is indicated for operation under load. In normal mode, it is up to 70 watts.
In total, we get a consumption of about 690 watts under load. If we take into account the rest of the system with powerful cooling, backlighting and so on, we take the consumption of another 80 watts under load and 40 in normal mode.
Thus, we get 770 watts under load and 230 with simple use. How much electricity does the computer consume per hour? These values will be the result, but it is necessary to take into account the efficiency of the power supply. Good expensive models provide 90%. That is, 100% will be approximately 850 and 260 watts, respectively.
Budget system
For the calculation we use the same principle as above. The low-cost 22-inch monitor from LG, which has FullHD resolution and a high-quality IPS matrix, requires only 23 watts. Agree, these are modest indicators, in comparison with the model above.
Since the system is budgetary and, let's say, just for work, we won’t separately consider the video card, but take into account the built-in processor. For example, select Intel i3. Under load, it consumes only 65 watts, but if the built-in video works, consumption reaches 120. In idle time, it will be about 50 watts.
Thus, for a budget system we get a value of 170 watts under load and 100 in idle. The approximate consumption of the rest of the system is also taken into account. Low-cost power supplies provide an efficiency of about 80%, which gives us power consumption of 195 and 120 watts, respectively.
Monthly calculation
It is very difficult to calculate how much electricity a computer consumes per month, since the difference in consumption between the maximum load and light work is huge. However, an approximate value can be calculated.
For example, a game assembly is used per day for 4 hours for games and about 3 in light mode. It turns out that the computer consumes 4120 watts or 4.12 kW during this time. For a month of such use, about 120 kW runs in. In the off state, if not disconnected from the mains, the system will take about 2 kW more.
The budget model, if you use it per day for complex tasks for only an hour and for games of 4 hours, consumes about 680 watts per day. For a month in this mode, the consumption will be 20 kW.
The difference between the two systems is, as we see, enormous.
Find consumption empirically
There are several more ways to find out how much power a computer consumes . Less accurate is found experimentally. For example, take a computer of medium power, which is great for games and work, but no frills. With light load it can consume about 150 watts, and in games up to 400 watts.
We turn off all the equipment in the apartment and leave one or several lamps with a total power of 100 watts. We turn them on and see how many turns the disk will make on the counter. Next, we do the same, but with a computer under strong and moderate load. Compare the number of revolutions.
For example, if the drive made 300 revolutions with the computer turned on under load, and only 100 with bulbs, respectively, the power consumption will be three times as much.
Accurate measurement
How much power a stationary computer consumes can be found in a more reliable way. In fact, you need to install a separate counter on your computer. This is a small device that plugs into a wall outlet and connects the system through it.
Such a device will accurately show the amount of energy that passes through it. It is quite easy to find on sale. How appropriate is the use of such a device with a relatively low consumption of the average computer, everyone must decide for himself.
How much power the computer consumes in sleep mode
In sleep mode or even completely off, the computer consumes electricity. For example, a screen connected to the network, but in the off state, consumes 0.3 watts, and in standby mode, it can consume up to 1.3 watts. In a month, you get up to 2 kW only on the screen.
The computer will take up to 20-40 watts in sleep mode, depending on the power of the system. Up to about 10 watts in hibernation mode. And in the off state, the power supply consumes up to 5 watts. This can increase the consumption by 2-15 kW per month, depending on the mode
How to reduce energy consumption
Always unplug your computer and monitor. Without unnecessary need, do not leave it in sleep mode. In the evening, reduce the brightness of the monitor, which will give noticeable savings.
In operating modes, when full performance is not required, for example, watching videos, working with documents, using a browser, and the like, you can switch the power consumption mode to economical. It will limit the system and help reduce consumption.
If your system is 8 years old or more, it's time to think about updating it. Even modern budget models will show higher performance with several times less power consumption.
How much power a computer consumes per day depends on the system and usage scenario. The difference between the budget model and the gaming computer, between the mode with high and moderate load can be very large. Each of them can be calculated in several ways, based on knowledge of the system, a simple experiment, or a special device - a wattmeter.