ASROCK B250M-HDV Handbuch Seite 19

2.4 Expansion Slots (PCI Express Slots)
There is 1 PCI slot and 3 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 x1 slot) is used for PCI Express x1 lane width cards.
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