Wattage needed for mid-high-extreme graphics cards

Hello fellow man, and possibly women. I was wondering, How much bigger of a power supply am I gonna need to upgrade my graphics card?

currently I have

a DVD drive

10,000 wd raptor HDD

micro atx mobo

AMD black edition processor

a wireless card

and a Saphire HD 2600 XT

Right now I have a thermaltake 430 watt power supply and have not run into any restarts and have successfully posted on every boot up. However it seems that on many systems that users have 500-700 watt power supplys and I don't know what much I need.


How many watts do I need for a mid/high range GPU