Any/all of them require modification to work in a G4. The mod revs the card to assembly rev "G1", which is marked on the card at the lower left side of the TDM connector. Revs below "G1" need the mod. You can easily tell if the card has the mod as well by inspecting the pcb at the right side of the Onyx chip. If the card has a little IC glued on to the board with green wires attached.