Asus Motherboard A8N-SLI SE User Manual page 91

PEG Root Control [Auto]
Allows you to enable or disable the PCI Express graphics root control.
Configuration options: [Auto] [Enabled] [Disabled]
PEG Buffer Length [Auto]
Allows you to set the PCI Express graphics buffer length. For optimum
performance, set this item to Auto.
Configuration options: [Auto] [Long] [Short] [Medium]
ASUS A8N-SLI SE 4-33