I have fiber optic DSL service, no telephone 100 Mbps. Have moved four months ago (two houses down), with the same service. In the old house, 50mbps with Pace 4111N modem, I routinely achieved 35mbps same room wifi performance. New house, 100mbps with Pace 5168NV modem. Same room wifi performance is 20-29Mbps. I've seen it go up a few times to 55-65Mbps, perhaps for half a day. Ethernet cable shows 75-85 and most often 100Mbps. ISP has no options for modems, and recommends a router. All we have are a couple of notebooks, a desktop, an iPad, iPhones and printer. No TV. All speed tests with one device connected.