Just plug in your components and it gives you a recommended wattage. If you’re not entirely sure about your PC’s power supply needs, check out this handy online calculator. A margin of error is a handy thing to have, not to mention the fact that having a little extra power gives you room to add more components in the future-like extra storage drives or cooling fans.

And since the graphics card specifications recommend at least a 400 watt power supply, that’s where we’ll start. 120mm fan for CPU cooler: under 10 wattsīased on these general figures, we can estimate that the How-To Geek desktop won’t use more than 350 watts under its full load.RAM: under 5 watts per DIMM – estimate 20 watts for our build.Graphics card (Radeon RX 460): 114 watts at peak.Here are the power requirements for the rest of our test build’s components: On Intel’s website, we see that the processor draws an average of 91 watts under high load. For example, our test machine at How-To Geek uses an Intel Core i7-7700K processor. If you want to estimate your power requirements, look at the specifications of each component in particular. These are typically require much lower power, and can usually get away with rough estimates. Other components also draw power, including hard drives, optical drives, and cooling systems like fans or radiators.