S = PCI - copper
EF = PCI express - fibre
PF = PCI express - fibre
ET = PCI express - copper
PT = PCI express - copper
XF = PCI-X - fibre
MF = PCI-X - fibre
MT = PCI-X - copper
GT = PCI-X - copper
http://forum.pfsense.org/index.php?topic=23934.0