Video: If you're building a killer PC gaming rig, you might need a high wattage power supply. However, some power supplies waste more power than others. Here's how to find out where yours sits. This video, from Linus Tech Tips, demonstrates how much electricity different power supplies draw from the wall, which is to say not much. Most higher wattage power supplies don't draw a significantly higher amount of power than lower wattage units.
However, the load you place on the power supply can have a more significant effect. A lower wattage power supply might start getting less efficient when you approach 100 per cent of the load that power supply can handle. This means that using 100 per cent of a lower wattage power supply may waste more electricity than using 50 per cent of a higher wattage unit's load capacity. Check out the full video for more details on how to build your rig to be as power efficient as possible and hopefully shave a little off your power bill.