New computer

[Your Computer]

Whatever you do, never cheap out on a power supply. If it overloads it is capable of irreparably damaging pretty much all of your system's components. 500 is the minimum for a modern gaming computer, 750 is OK (what I have), 850 is more than enough and 1000 and above is for overclockers and rich people.

Newer motherboards should have some kind of protection against an undesirable increase in voltages. Nevertheless, even overclockers would know buying a 1000w power supply is going overboard. You have to remember, whatever the system isn't using gets converted into heat. The power supply can easily overheat if you've bought a 1000w power supply and your system only needs 450w.