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October 13, 2023

How Much Headroom For Power Supply?

When you buy a power supply, there's a good chance that it will have more wattage than your PC actually needs. This extra wattage is known as headroom. Having this headroom ensures that your power supply can handle the current spikes that will occur during heavy use, such as when playing games or editing video. This also helps to protect your power supply from burning out or failing.

There are a few things that influence how much headroom your power supply has. The first is how many cables it comes with, which depends on how large the case is and what wattage you're looking at. The second is the efficiency of your power supply. Higher efficiency ratings offer more headroom, since less of the power is lost to heat.

You should also consider how much headroom your power supply has on the different DC voltage rails. These are the individual wires that carry different DC voltages, such as 3.3V, 5V, and 12V. The components in your computer draw power from these rails, with most of the important parts requiring 12V.

To determine how much headroom your power supply has on each of these rails, you can use a tool like Outervision's PSU calculator. It'll show you how many watts the power supply can provide on each of these voltage rails at a given load and efficiency rating, as well as how much headroom it has on all of them.