MSI X299 TOMAHAWK AC Quick Start Manual page 30

Multiple graphics cards installation recommendation
PCI_E1
Important
For a single PCIe x16 expansion card installation with optimum performance, using
y
the PCI_E1 slot is recommended.
If you install a large and heavy graphics card, you need to use a tool such as MSI
y
Gaming Series Graphics Card Bolster to support its weight and to prevent deformation
of the slot.
When adding or removing expansion cards, always turn off the power supply and
y
unplug the power supply power cable from the power outlet. Read the expansion
card' s documentation to check for any necessary additional hardware or software
changes.
20
Overview of Components
PCI_E1
PCI_E4
PCI_E1
PCI_E4
PCI_E6