IX: Give it power, choose a PSU


A power supply unit (PSU) is the last component for the computer and probably the most overlooked of all of them. The PSU gives power to all your computer so you need a reliable and good quality unit to prevent problems with the power supply and to improve long term reliability.

The first thing to do when you are going to choose the PSU is to have an estimation of the power you need for your new computer. In online builders as pcpartpicker will give you directly the value, another great advantage to use them for your build. Or you can calculate it by yourself looking the specifications. Remember that you are looking for continuous power, not peak power.

Once you know the value of the power required you need to choose a unit that can handles more than that. Usually, these units have their peak of the efficiency at loads lower than the 80, so the recommendation is to get a PSU where you are using the 50-60 percent of the maximum output power. If you do it, you will maintain the unit at a good working load and you will still have some room for improvement.

Look always for quality brands, you can always check how well it performs doing a little of research in internet and comparing user reviews of the components. If you are wondering why the quality is so important if you just need it to give power, that’s because these units are dedicated to handle power, which means that the internal components require to handle more current than components in other parts of your computer. This in general means more wear due to work under higher power. If you buy a cheap unit with cheap components, there possibility of failure is higher than in a good quality unit with quality components. And remember that without power, your computer won’t work

The key things you will look for in your PSU:

  • Wattage: The most important thing because you have to be sure that the unit can give enough power for all your components.
  • Type: It has to be the same as your motherboard and your case to have the correct connectors
  • Efficiency: As usual, look for high efficiency and you won’t waste energy
  • Connectors: In general any PSU will have more connectors than you require, yet it is good practice to check that all your components have their own connection
  • Modular or hard wired: This is optional but usually handy. Some PSU have all the wires hard-wired so you just have to deal with all of them. On the other hand, some units allow you to connect only the wires that you require, which leaves a cleaner look. So it basically depends if you want to deal with all the cluttering. Modular units are usually a little more expensive so if you want to save some money and your case doesn’t allow to see the internals of your computer you are set with a hard wired PSU. Yet, if you want to show off how good your computer looks, you probably have to go for a modular PSU.