The basis for picking a correct power supply is simple. You are building your own computer (not buying a package from the store), and thus, you need to pick a power supply to suite your needs. Without a doubt, different types of graphics cards, more drives, and everything in between will require different types of power supplies.

So without further ado, lets get started.

299 Watts or Less

These types of power supplies are probably not even on your radar. If your a building a machine that only needs 300 watts (or less), it probably really only needs it to run some very basic applications, and certainly not any higher end hardware. Still, this type of power-supply is recommended for net-books, notebooks, and machines that have a very simple purpose.