I didn't search, so I apologize if this has been posted before. I don't see it stickied. This is from newegg.com and below is their note.
Newegg Power Supply Calculator
http://educations.newegg.com/tool/p...ons.newegg.com/productfinders/powersupply.jpg
NOTE:
The PSU Wattage we recommend only gives you a general idea on what to consider while selecting a power supply. PCI cards, External devices, USB and Firewire devices, Cooling fans and other components may need more power.
Newegg Power Supply Calculator
http://educations.newegg.com/tool/p...ons.newegg.com/productfinders/powersupply.jpg
NOTE:
The PSU Wattage we recommend only gives you a general idea on what to consider while selecting a power supply. PCI cards, External devices, USB and Firewire devices, Cooling fans and other components may need more power.