- Created on 21 February 2006
Power Supply Unit. This is the box which supplies power to the rest of your computer. A PSU is rated to a certain number of watts. If your PSU doesn't supply enough watts, your computer may become unstable. When choosing a PC power supply is it is important to calculate the power required (in watts) in total for every device that will be built into the system.
There are many calculators designed for this purpose and in our opinion the best and most comprehensive is the eXtreme Power Supply Calculator which provides a simple menu based interface for selecting your desired components. It then provides an estimate of the wattage rating that your new power supply will require as a minimum to run them.