I was gonna buy the new Dell XPS 700 when I saw the different choices I had available for the video cards. My question is which is better and why the new 1GB NVIDIA GeForce 7950 GX2 Dual-GPU Graphics Card or Dual 512MB nVidia GeForce 7900? All I know about the 7950 GX2 is that basically it's 2 video cards combined into one. Please I could use all the help I could get. Thanks again.