Also, how do i find out how much power this card needs? I don't know if my PC's power supply can deliver what it takes.
"He remembered that they were but flesh, a passing breeze that does not return"
Well, it says it is. Look at the overview.

Quote by The Overview
The Sapphire X1950 PRO makes for a welcome addition to the family with its robust hardware offerings such as: the industry acclaimed X1950 GPU, 256MB of GDDR3 of onboard memory, CrossFire support, DirectX and OpenGL acceleration along with enhanced support for the Windows Vista 3D environment.
Quote by Fallon, Jones & Sage Francis

"By the way my name is Marcus. But if you like you can call me Sensei."

American Idol - or as I call it, the Gong Show Rip-Off

According to #Yeezuz, Kanye West is a god. As if I needed more reasons to be an atheist.
Windows Vista doesn't need a DX10 card, but it does mean that games within the next few years will eventually need a DX10 card. Remember that most games are still playable with a DX8 card.

To run Aero Glass in Vista you need WDDM drivers for your card - DX10 isn't really the key factor.
Every inside out badger has a silver lining.