Recommended Power Supply CalculatorThe power supply calculator at the bottom of this narrative is an important tool to assist you in determining the watts needed by a power supply to power a desktop computer. A calculator should not be totally relied upon in the selection process; other things also need to be considered before purchasing.
The total Watts is important but the Total Amperage Available on the +12V Rail(s) is the most important, followed by the +5V amperage and then the +3.3V amperage. Because of the increased power consumption of the new high-power video cards the recommended minimum for +12V is 26A, for SLI 35A.
We highly recommended that you add 30% to the total watts the calculator determines to cover things such as Capacitor aging, peak efficiency, and future upgrades. Please post any questions or concerns about your power needs on the forum so one of our Hardware Techs may offer a personal evaluation on any power supply selections or answer questions that are appropriate to your needs.