* Ian D:

Asus also uses PEG. The choices in BIOS are PEG/PCI
and PCI/PEG. The problem is that they don't explain
the meaning of PEG on the manual page for those
settings. Maybe they thought it would be too confusing
to use PCIE/PCI.

No. The reason for using the term "PEG" simply is because some standard
mobos support gfx only in the PEG slot and not in all PCIe slots.

Benjamin