How to check the power consumption of your PC
With energy costs increasing in the last number of years and many opting to be more environmentally conscious, people have started to analyze the energy consumption of the devices around them. A computer is one such device that would rank among the highest energy consumers in anyone's household, and we'll be showing you how to get both a rough estimate and a very accurate measurement of your PC's total power consumption.
How to measure your PC's power consumption using an online calculator
Not totally accurate, but a good indication
Pretty much every part inside of your computer has a maximum rated wattage that it can operate at, with the part consuming significantly less power when at idle. We can use this information to our advantage to calculate the maximum amount of power that a computer will consume, so long as you know its specifications. OuterVision's online calculator is the best calculator for this, but it's not 100% accurate.
Once you have filled in all of your specifications, it will give you a rough estimate of how much power your PC should consume, and also what power supply you'll need to facilitate the parts that you have onboard. It will also calculate the yearly cost based on those numbers, so that you can get a feel for how much your computer costs to run month to month and year to year.
As already mentioned, this tool is not completely accurate, but it's great at giving an estimate of how much power you should expect your build to consume. If you don't know every detail about your PC, there's also a "basic" tab that you can use to calculate, but this will understandably be less accurate.
How to use software to measure your PC's power consumption
It also won't be totally accurate
If you want to get a better grasp of how your own computer fares in terms of energy usage, you can try using a tool such as Open Hardware Monitor or HWInfo. This will show you the wattage drained from individual parts, most notably the CPU and the GPU, which are the two biggest drainers. While you'll need to add them up individually, it can also give you a great idea of how much power your system is consuming. it also won't pick up every component, but the CPU and GPU are the two largest drains by far, anyway.
How to measure your PC's power consumption using special hardware
A power monitor is the most accurate way to check
If you want to be completely accurate, then the best way to measure your PC's power consumption is with a watt meter. A great tool for this is the P3 Kill A Watt. You plug it into the electrical outlet, and then plug your computer into the Kill A Watt. It will then light up and show the current wattage being drained, and you can then test your computer in a number of scenarios to get a sense for how much power is being used at any given time.
This is the best way to measure by far, but will also actually cost you money. This particular monitor is considered one of the best for someone just occasionally taking readings like this, and it'll set you back anywhere from $20 to $40.
P3 P4400 Kill A Watt Electricity Usage Monitor
FAQ
Q: What consumes the most power in a PC?
Typically, inside of your PC, both the CPU and the graphics card consume the most power. When your computer is at idle, it's likely only your CPU will be using any sizable amount of energy. This will also depend on your CPU.
Q: Can I leave my PC on all the time?
If you want to leave your PC on 24/7 you can, but be warned that it may consume a lot of energy over time. It depends on the parts that you are using, as less powerful CPUs will typically use less power overall. We recommend keeping an eye on your power usage and seeing how it fares before deciding to leave it on all of the time.