HyperTransport voltages can to from 1.22V to 1.50V.
Chipset voltage can be changed from 1.22V to 1.5V.
The PCI Express link width can be set from 1X to 16X for each 16X slot. With two cards both would be set to 8X to use the full 16X available. The PCI Express clock can be set from 100MHz to 200MHz which is quite a high range.
PCI E voltage can also be manipulated for the 1.2V supply, and the 1.8V supply.