Asus P5E3 Premium/WiFi-AP@n - Manual (Page 46)

2-20 Chapter 2: Hardware information
2.5.4 PCI slots
The PCI slots support cards such as a LAN card, SCSI card, USB card, and other
cards that comply with PCI specifications.
2.5.5 PCI Express x1 slot
This motherboard supports PCI Express x1 network cards, SCSI cards and other
cards that comply with the PCI Express specifications.
2.5.6 PCI Express 2.0 x16 slots (blue)
This motherboard has two PCI Express 2.0 x16 slots that support PCI Express
2.0 x16 graphic cards complying with the PCI Express specifications. With two
graphics cards installed, the motherboard can enable dual-display.
This motherboard supports two ATI CrossFire™ PCI Express 2.0 x16 graphics
cards that comply with the PCI Express specifications.
2.5.7 Universal PCI Express x16 slot (black)
This motherboard also supports a Universal PCI Express x16 slot with a maximum
speed of x4 or x1 link. The operating frequency of this slot changes depending on
the type of PCI Express card you install.
PCIe 2.0 x16_1 slot (blue, @x16)
PCI Express x1_1 slot
PCIe 2.0 x16_2 slot (blue, @x16)
PCI slot 1
PCIe x16_3 slot (black, @x4 or x1)
PCI slot 2