powermac differences

[Terminills]

Both machines use an AGP video card slot, but the fastest G4 is only 4X while the G5 is 8X.

Depending on the model the G5 features PCI and PCI-X expansion slots while the G4 uses 64bit PCI slots.

Some G5 models had PCIE.

http://www.everymac.com/systems/apple/powermac_g5/specs/powermac_g5_quad_2.5.html

Not that it matters right now since MorphOS doesn't support them yet or at all.