It's been a while since we did a group test of PC power supplies, so today we'll take a closer look at 19 PSUs in the 500-550 watt segment.

While 500 watts might sound low in the ears of most hardware enthusiasts, for the vast majority of PCs it's more than enough. The TDP, or Thermal Design Point, of most current processors is between 65 and 95 watts. Only Intel's high-end Socket 2011 models and certain AMD processors use up to 130 watts. The most high-end cards use up to 250 watts, but typically much less. The motherboard and RAM modules use a few dozen watts more, along with a few watts for the casefans.

For example, a PC with an Intel Core i7 4770K processor and a GeForce GTX 770 graphics card will never need more than 350 watts. With a Core i7 4960X and a GeForce GTX 780 Ti that would be around 450 watts. That means a power supply of 500-600 watts is enough for a very powerful, state of the art PC. Only if you want to overclock or add a second video card do you need a more heavy duty PSU.