The cost of electricity keeps rising, bills cause mini-heart attacks, and sooner or later your gaze lands on your computer. If you have marathon sessions every day, you've probably already wondered if there's a way to reduce its consumption. However, no strategy will be valid if you don't take some readings first. So, if you want to know how many watts of electricity your PC uses, you should read this.
Software isn't much help
The web is full of calculators for ATX power supplies, and we've previously talked about programs like Core Temp and HWiNFO, but beyond what an internal sensor or a website indicates, the truth is we're dealing with educated guesses, estimates. In other words, these tools only give you a basic idea about the real or potential consumption of your equipment, and you can't trust their results 100 percent. It might not be a good economic moment for you, but if you want more accurate readings... you'll need hardware.
The clamp meter
With a clamp meter connected to one of the cables and a bit of math, all calculation errors and sensors disappear completely. Logically, that doesn't make the clamp perfect, but it enables a much better reading process. Also, many clamps can measure volts, and that brings us straight to Volt x Ampere = Watt. If your home's alternating current is 220V and the clamp registers 0.5A, the computer (or any other appliance) is using 110 watts.
The smart meter
Now, using the clamp meter isn't entirely comfortable for a beginner (you have to measure a single cable, otherwise the reading will always show zero), so we must mention the smart meter. Depending on the model and manufacturer, these devices can report volts, amps, watts, kWh, or all at once. They are Plug & Play, very easy to use, require no modifications, and their price is very reasonable (less than 30 euros).
Limitations
To finish, it's necessary to highlight a small detail: The wattage 'at the wall' doesn't represent only a computer's consumption. After all, there will always be 'loss' in the cables, and with each additional regulation/conversion process. Even so, direct real-time readings using dedicated hardware remain your best option. Good luck!
