I just recently upgraded my internet to xfinity's gigabit. Speed tests were giving me 190mb - 200mb downstream. I called the ISP and told them I was not getting the gigabit speed. They told me to connect a wired device straight to my modem (MB8600), check speed there, which I did. The only wired device I own is a 10 year old Dell Inspiron, purchased a D-Link PCI Gb card for it, made sure to use cat 5E between it and the modem, no changes in new speed tests. I told xfinity to send me a tech, service call. I just want you to show me that I actually have Gigabit coming to my modem, I'm responsible from there on. Well, he took one of xfinity's modem/router, hooked it up to my line and showed me 900mb downstream (WiFi) on speed test through his cell phone. We hooked the same modem, same patch cord to my desktop, no change at all in online speed tests. What am I missing here? Is my computer so old the architecture wont support gigabit? I don't plan to leave this desktop connected to the modem, everything I have is wireless and comes off my router (Linksys WRT 3200ACM), but if I should use this old Dell on wired connection, how would I get it there? Thanks in advance for any advice.