Just upgraded to gigabit speeds with Suddenlink. Using my own modem and router to save money, however can't get hardwired (6ft cat5e) speed over 400mbps. I thought the DGL-5500 could support gigabit speeds? I updated to the 1.13FW but didn't see any difference. With SB enabled, I was getting <200mbps so I turned that off and pretty much returned it to factory settings and am getting in the high 300s now but still that is well over 500mbps off from what the modem is providing (low 900s). I haven't even tested the wifi speeds because my xbox and computer are wired to the router so I'm not really concerned about that. I know it's a really old router but I would like to use this router still if it is actually possible to get at least close to 900mbps from it. Any help or advice is greatly appreciated!
Modem: Arris SB6190 (gets 930mbps hardwired directly to computer with cat5e)
Modem-to-router cable: cat7, tested and works (also get same speeds with other cat5e ethernet cables)
ISP: Suddenlink
Region: Texas