X1950 vs GeForce 7950GX2?

Which is better, the ATI Radeon X1950 or the Nvidia GeForce 7950GX2?

http://www.ati.com/products/RadeonX1950/index.html

http://www.nvidia.com/page/geforce_7950.html

Also: my power unit is 300W, new card is gonna need a 600W, can anyone suggest a good new one that’s not too expensive?

Needs to be PCIE compliant with combined 12V current rating of 40A

My m’board is an Asus P5LD2