MSI MEG B550 UNIFY-X Quick Start Manual page 34

4xM.2 PCIe SSDs + 4xSATA HDDs
M.2 PCIe
M.2 PCIe
M.2 PCIe
M.2 PCIe
For Chipset mode these two
PCIe x1 slots are un-available.
(Default)
For CPU mode these two PCIe x1
slots are available.
22
Overview of Components
2xM.2 SATA SSD + 2xM.2 PCIe SSD
+ 5xSATA HDDs
M.2 SATA
M.2 PCIe
M.2 SATA
M.2 PCIe
For Chipset mode these two
PCIe x1 slots are un-available.
(Default)
For CPU mode these two PCIe x1
slots are available.