I got my answer. The Ati FirePro V3700 graphics card arrived. It's PCI Express 2.0 and there was instant recognition. The install was very smooth and after checking out applications (heavily graphical), everything works perfectly. I'd heard that 2.x Nvidia cards have problems with 1.0a, but this wasn't a problem with me since I always use ATI. As usual, ATI didn't let me down. I don't know how PCI-e 2.1 would work but ATI 2.0 is perfect.