I am currently installing a new network and am wishing all workstations to run 100 MB to my NT Servers. My question is, the bulk of these workstations have integrated on board ETHERNET (Q610, Q630, Q650, PM 7600/120, 7200/75) shipped from Apple. Can this Ethernet be upgraded to support 100 mb? Will it already support 100 mb? If a new card is added how is the old one disabled?