Dell XPS 600 - Manual (Page 83)

Removing and Installing Parts
83
NOTE:
If a graphics card is installed in each of the PCI Express x16 card slots in the dual-graphics
configuration, the PCI Express x1 card slot is not accessible for use.
• One PCI Express x1 card slot
PCI card
PCI Express x16
card
PCI Express x16
card slot
PCI Express x1
card
PCI Express x1
card slot