This is for ChrisM and any other video card experts.  I've searched these forums and have found conflicting answers.  I have an XPS 600 and started having problems with my video card (nVidia 7900GS).  I had dozens and dozens of stuck pixels plus lines of colored pixels whenever I scrolled my screen.  I thought it was the monitor (2407FPW), but after working with tech spt, they decided it was the video card.

 

The technician came today and replaced my video card and the good news is that it did fix all the problems I was having.  However, he replaced my 7900GS with a 7800GTX.  I am really having a hard time trying to determine if this is a downgrade, an upgrade, or an equal replacement.  Please help.  Thanks.