ASROCK X99 WS Manual Del Usuario página 20

2.4 Expansion Slots (PCI Express Slots)
here are 6 PCI Express slots on the motherboard.
Before installing an expansion card, please make sure that the power supply is
switched of or the power cord is unplugged. Please read the documentation of the
expansion card and make necessary hardware settings for the card before you start
the installation.
PCIe slots:
PCIE1 (PCIe 3.0 x16 slot) is used for PCI Express x16 lane width graphics cards.
PCIE2 (PCIe 3.0 x16 slot) is used for PCI Express x8 lane width graphics cards.
PCIE3 (PCIe 3.0 x16 slot) is used for PCI Express x8 lane width graphics cards.
PCIE4 (PCIe 3.0 x16 slot) is used for PCI Express x16 lane width graphics cards.
PCIE5 (PCIe 2.0 x16 slot) is used for PCI Express x4 lane width graphics cards.
PCIE6 (PCIe 3.0 x16 slot) is used for PCI Express x8 lane width graphics cards.
* If M.2 PCI Express module is installed, PCIE3 will be disabled.
PCIe Slot Conigurations (For CPU with 40 PCIe lanes)
Single Graphics Card
Two Graphics Cards in
CrossFireX
Mode
hree Graphics Cards in
3-Way CrossFireX
or 3-Way SLI
Four Graphics Cards in
4-Way CrossFireX
or 4-Way SLI
18
PCIE1
x16
TM TM
x16
or SLI
TM
x8
Mode
TM
Mode
TM
x8
Mode
TM
Mode
PCIE2 PCIE3 PCIE4
N/A N/A N/A
N/A N/A x16
x8 N/A x16
x8 N/A x8
PCIE5 PCIE6
N/A N/A
N/A N/A
N/A N/A
N/A x8