The power supply unit (PSU) is the heart of every PC, gaming or not. It takes alternating current power from a wall outlet and converts that power into a low-voltage direct current power, which then goes on to power all components of the gaming pc. Therefore, it is extremely important to choose a reliable and steady power supply to power your motherboard, CPU, RAM, graphics cards, drives and fans. The wattage rating of a power supply describes how much power it can supply. The amount of power needed depends on your pc components and what applications the pc is running. If the pc has multiple grahics cards, you may need a power supply capable of 850w+. Basic pc builds that have one graphics card and a less capable CPU, may be able to run off of a 500w capable power supply. Power supplies are rated based upon the efficiency by which the unit converts AC to DC power. Power supply ratings rank from bronze all the way through titatnium. For the best results in a PSU, you want to select a power supply unit that is 80 plus certified. This means the unit must deliver at least 80% efficienty at 20%, 50%, and 100% of max load. Tools such as PSU calculators, aid in choosing the correct PSU of pc builds. (Cross, 2020).