High power draw Choosing between a 500W, 850W, and 1000W power supply largely depends on the PC you intend to supply power to. Most PCs can get away with a 500W PSU, especially if you're running an AMD Ryzen 7 or Intel Core i7 CPU with a single GPU. A modern 500W PSU from a reputable brand will provide ample stable power at full load. You only need to go to above 500W if you plan on overclocking, using a more powerful CPU or GPU, and want to add additional hardware. The best power supply doesn't necessarily need to have the highest power output.