Consumed power of each device can be ascertained by checking its specifications on the manufacturer's website.
One of the main consumers of electricity in the system unit processor. Its power consumption ranges from 45 W (Core 2 DUO E6300) to 135 watts (Pentium 640). It is necessary to take into account that overclocking increases this figure by approximately 25% for every 10% overclocking.
Motherboard can consume 15 to 30 watts. In "device Manager" view, which integrated devices are contained on the motherboard of your computer: sound card, RAID devices, network adapters. They increase the power consumption.
The video card requires from 50 to 130 watts. This figure fully depends on the performance of the video card and depending in what mode it works. Additional power increases the power consumption almost in 2 times. Heavy-duty – 3D graphics, high screen resolution, working with powerful graphic editors – also increase the power consumption. When calculating take into account the mode of operation of the adapter.
Power required hard drive, depends mainly on its condition. Peak loads have to turn on, when you run diagnostics of the hard drive, searching for files when the heads are moved over the surface of the magnetic media, and copying large amounts of information. On average 15-60 watts. Consider what actions you often perform on your computer.
Optical disc drives consume 10 to 25 watts. Most energy is consumed when high-speed recording, and when reading the low quality disc when a rotation speed is constantly changing. Very large power consume harvesters – devices that can write CD and read DVD.
The power consumption of a sound card depends on the class. The higher the sound quality, the more power is required for its reproduction. The average sound card required 5 to 10 watts. Go to the website of the manufacturer to yield input power your sound card.
The cooling fan requires 1-2 watts. Because in the modern system unit to them, as a rule, not less than two, multiply the average power by the number of the fan to calculate their total power.
To know the energy consumption of your computer , you can online calculators. Go to the website and enter device data into the appropriate Windows. The program will calculate the power consumption of each component and the system as a whole.