This page is designed to provide general information on a particular category. For information on individual products please refer to the help button () on the right hand side of the configurator.
A PSU is the Power Supply Unit for your computer. The average PSU ranges from 350W up to and above 1000W. When configuring your computer we will automatically check that the power supply you have selected will be sufficient for the components you have configured and alert you if there are any problems.
As a rough guide, the following components use:
5W (Per Stick)
Low-End Graphics Card
Mid-Range Graphics Card
High-End Graphics Card
PCI Cards (e.g Wireless Card)
7W (per card)
Floppy, Keyboard & Mouse
As you can see, the minimum power supply you should have in a desktop computer is approximately 350W from doing a little maths, but if you're willing to spend that little bit extra, you can get a more powerful power supply with an ultra quiet cooling system or modular wiring.
A Popular question
Q. I think I need a really powerful power supply, and I have seen a 600W or above model for around £20 - £30 in the shops. Why are your power supplies more expensive?
A. There are no rules that are set in stone governing how you can rate the wattage of a power supply, and naturally people think that more power is better. The rated wattage of power supplies we sell are the true, constant power output and not the peak output. (Peak output is that power that a power supply can output for a few seconds.) Not naming any brands, if you search the high street, you can purchase what apparently appear to be 600W or even 700W power supplies for around £20, but be warned - these are likely to be power supplies that have been rated on their peak output and not their constant output. Some power supplies do not even give their stated output at peak. For a 600W or above power supply with a true constant output using reliable components, you should be looking at paying anything from £50 upwards.
Our high end power supplies (even though they may only be 400W - 500W) are tried and tested to give your computer a constant supply of quality power. Component manufacturers, such as graphics card manufacturers often over label the power supply requirements of their cards to cover for PSU manufacturers who have labeled power supplies as peak output and not constant output.