Video Card vs. Power Supply

Hey Guys,

I’m upgrading the video card in my pc. I wanted to upgrade to the Ge Force 7950GT However, it requires a minimum of 350W power supply w/ a 20amp +12v connector. So I called HP and ordered a 400W power supply that that would fit right in my tower. I have 2 hard drives and a Intel Core 2 Duo 2.2 Ghz processor. Do you think this power supply is large enough to handle the video card I want to install? Also I don’t know if the power supply has a +12v 20amp connector or not?