Some server vendors block the eSATA card in BIOS, or have physical connectivity limitations with their expansion bus risers. You may require an updated firmware to enable the eSATA card. In the case of Dell Poweredge 2x50 servers, it has been reported that the Micronet eSATA card is only supported on the 4 lane (4x) slot and not the 8 lane (8x) slots. For more information please consult your server's user manual or support website.