The most important part of your Rig, don't skimp out on cheap power supplies or you will regret it.

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Coolermaster Masterwatt Lite 500
£39.00
Advanced Circuit Design Silent and Durable Fan Green Power 500W 80plus
Powercool 550W semi modular PSW
£49.00
Black Coloured PSU with a 140mm Silent Cooling Fan Equipped with a Single 12v Rail Delivering upto 36 Amps Equipped with 2 PCI-E Connectors..
Coolermaster Masterwatt Lite 600
£49.00
Advanced Circuit Design Silent and Durable Fan Green Power 600W 80plus
Coolermaster Masterwatt Lite 700
£59.00
Advanced Circuit Design Silent and Durable Fan Green Power 700W 80plus