HP ROM-Based Setup Utility - Manual (Page 118)

PCIe Slot6 Training Speed
NOTE: This option is available on some G6 servers with Intel processors.
This option controls PCI express slot 6 only and does not impact the operation of PCIe slots 1-5.
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PCIe Generation 2 (default)
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PCIe Generation 1
118 RBSU menu-driven interface, version 3.xx or later (G6, G7, and Gen8 servers)