Have a look at this post: Solved: Dell Precision T7910 support for PCI video cards - Dell Community
Not sure why dell included this at all.  Seems like a waste of a PCI slot.  Here is the specs: SLOT5 - PCI 2.3 (32 bit, 33 MHz), 133 MB/s Any ideas about what I can use it for?  Thanks!
T7610 - What is the PCI 2.3x slot good for?