Hello. My Broadcom Netlink Gigabit ethernet adapter runs at 10 mbs, wireless runs at 30 mbs on my Dell XPS 8300. Have Motorola cable modem and Linksys 3200 dual band router. Tried a new cable with same results. Tried different ports with same results. Tried a laptop and got 30 mbs with ethernet cable. Updated the driver for the Broadcom and no improvement. I suspect the card is bad. Anything else I should check before buying a new ethernet card?