I want to upgrade my PSU, how can I calculate the wattage my system requires?

There are a number of PSU load calculators available online with which you can calculate whether your system upgrades require also upgrading the power supply unit.

For the link below you will need to input the Processor, Graphics Card, and Number of Hard Drives. Also designate whether or not the system is overclocked. Then click the Calculate tab.

http://www.corsair.com/learn_n_explore/