I have a 1.5 Gbps internet plan, and my provider confirmed that the modem is receiving excellent speeds—about 1,641 Mbps download and 1,040 Mbps upload when tested directly on the modem. However, speed tests run from my computer show only around 100 Mbps, and downloads usually top out at roughly 10–12 MB/s.
A few weeks ago, I used the same computer and Ethernet cable at a friend's home with a 500 Mbps plan and downloaded at about 40–50 MB/s. There haven't been any computer updates or hardware changes since then. I'm trying to figure out what is limiting the connection at home.
4 Answers
The modem’s internal speed test only proves that the provider is delivering the advertised speed to the modem. It doesn’t guarantee that every device, cable, router, or server beyond that point can use the full 1.5 Gbps. Run the test with the computer connected directly to the modem using a known gigabit-capable port and cable. If it is still limited to 100 Mbps, inspect the computer’s Ethernet adapter settings or contact the provider for an on-site check.
Something between the computer and the modem is probably limited to Fast Ethernet. Check the Ethernet link speed on your computer and confirm that it negotiates at 1.0 Gbps rather than 100 Mbps. The cable should be at least Cat5e, and an older router, switch, wall jack, adapter, or network card could also be the bottleneck.
You can also try disconnecting and reconnecting the Ethernet cable, then renew the network address with the operating system’s network commands. If the link still shows 100 Mbps, resetting the connection won’t overcome a hardware or port limitation, so focus on identifying which device is negotiating at that speed.
First, check the units. Internet plans and speed tests normally use megabits per second (Mbps), while download programs often show megabytes per second (MB/s). A 100 Mbps connection works out to roughly 12 MB/s, so your 10–12 MB/s download rate strongly suggests the connection is negotiating at exactly 100 Mbps.
That matches what I’m seeing: the browser speed tests show about 100 Mbps, while downloads show around 12 MB/s.
I’m using the same cable that reached 40–50 MB/s at another location, but I’ll check the negotiated link speed and the other hardware in the connection.