A computer is a substantially complex device and each one of its hardware parts, including the processor, motherboard, peripherals, and accessories require varying amounts of electrical power. The total power consumption of a computer is decided by the sum total of electrical power requirements of all the hardware parts. The power rating of the processor, hard drive types used, power rating of the graphics card, optical drives, memory modules, and overall usage pattern decides the amount of power consumed by a computer.
The SMPS or the power supply of the computer is designed to provide adequate power to all these parts. Usually, branded desktop manufacturers may provide you with an estimate of the maximum power consumption in manuals, but the actual consumption is much lesser. Basic tasks like word processing consume less power, while gaming, burning DVDs, and other such complex tasks make the computer consume more power.
Electrical Consumption of Desktop Computers
A desktop computer may use anywhere between 60 watts to more than 250 watts of power. Add to this, about 75 more watts of power consumed by an LCD monitor. This takes the total power consumption to a range between 135 watts to more than 300 watts. Of course, the actual power consumption will vary according to the configuration of the computer and its usage.
Electrical Consumption of Laptop Computers
Compared to a desktop computer, a laptop uses substantially lesser amount of power. An average laptop will consume about 45 to over 70 watts of power. So, for prolonged usage, a laptop is certainly a better option, compared to a desktop, from the power-saving viewpoint. If you want to determine the amount of electricity a computer uses in a day, multiply the hourly consumption by the number of hours for which, the computer is used. To get a cost estimate of the consumed power per day or month, divide the value of total power consumed, by 1000 and multiply it by the cost of electricity per kilowatt hour, charged by your electricity company.
Tips to Save Power
In sleep mode, a computer uses less than 10% of the power used in operating mode. Only 6 watts to 15 watts of power will be consumed when the computer is in the sleep mode. So choosing a power saver plan and letting the PC go to sleep or hibernate, when not in use, is a good way of saving electricity.
If you use an LCD monitor, keeping the brightness levels of the screen to be low, it will use up a lesser amount of power. Screensavers do not save power but only entertain. Switching off your computer is a better option, compared to letting it sleep or putting it on standby. Follow these economy tips to bring down the electricity bills.
To conclude, know that the average range of electrical power used by a desktop computer is around 60 watts to upwards of 250 watts, while laptop power consumption is about less than half of that.