1-9
1.2.5 Expansion slots
Unplug the power cord before adding or removing expansion cards. Failure to do so may
cause you physical injury and damage motherboard components.
Slot No.
Slot Description
40-LANE 28-LANE
1 PCIe 3.0/2.0 x16_1 slot PCIe 3.0/2.0 x16_1 slot
2 PCIe 3.0/2.0 x16_2 slot PCIe 3.0/2.0 x16_2 slot
3 PCIe 3.0/2.0 x16_3 slot PCIe 3.0/2.0 x16_3 slot
4 PCIe 3.0/2.0 x16_4 slot PCIe 3.0/2.0 x16_4 slot
5 PCIe 3.0/2.0 x16_5 slot PCIe 3.0/2.0 x16_5 slot
6 PCIe 3.0/2.0 x16_6 slot PCIe 3.0/2.0 x16_6 slot
7 PCIe 3.0/2.0 x16_7 slot PCIe 3.0/2.0 x16_7 slot
The default setting of PCIe x16_2 slot is in Auto mode, which automatically optimizes the
system bandwidth. ASUS Thunderbolt EX card is supported on PCIEX16_2 slot (Gen 2)
and automatically runs at x2 mode.
E13611_X99-E_WS_USB31_UM_V4.indb 9 10/27/2017 16:56:01