Lanner NCA-5710 - Replacement PCIe Module Guidelines

Appendix C: PCIe Hot-Swap
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In a typical PCIe-based system, the enumeration and resource allocation algorithms performed by the CPU
during the very first initialization will fix the PCIe topology, meaning that the configuration of the PCIe
modules first installed in the slot is locked down and not allowed for alternation. Considering this limitation,
for hot-swapping, it is strongly advised that you always replace a PCIe module with one of the same link
width. The table below shows other possible choices of link width of a replacement PCIe module.
Replacement PCIe Module(s)
The PCIe Module(s)
First-installed in the slot
One x4 module
Two x4 modules
One x8 module
No modules installed
O
X
O
One x8 module installed
O
X
O
One x4 module installed
O
X
X
Two x4 modules installed
O
O
X