ASROCK Z170M Extreme4 Manual page 19

2.4 Expansion Slots (PCI Express Slots)
There are 4 PCI Express slots on the motherboard.
Before installing an expansion card, please make sure that the power supply is
switched off 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 x1 slot) is used for PCI Express x1 lane width 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 x4 lane width graphics cards.
PCIe Slot Configurations
Single Graphics Card
Two Graphics Cards in
TM
CrossFireX or SLI
Mode
Three Graphics Cards in
3-Way CrossFireX TM
For a better thermal environment, please connect a chassis fan to the motherboard's
chassis fan connector (CHA_FAN1 or CHA_FAN2) when using multiple graphics
cards.
PCIE1
x16
TM
x8
x8
Mode
PCIE3 PCIE4
N/A N/A
x8 N/A
x8 x4
Z170M Extreme4
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