My internet plan is rated for 1.5 Gbps, and the provider confirmed that the modem is receiving about 1641 Mbps download and 1040 Mbps upload. However, speed tests run on my computer through both Google and the provider's website show only about 100 Mbps. At my apartment I normally download at roughly 10–12 MB/s, while the same PC and Ethernet cable reached around 40–50 MB/s at a friend's house with a 500 Mbps plan. There have been no PC updates or hardware changes. What could be limiting the connection, and how can I troubleshoot it?
4 Answers
First, check the units. Internet plans and speed tests usually show megabits per second (Mbps), while download programs often show megabytes per second (MB/s). A 100 Mbps connection works out to roughly 10–12 MB/s, which matches your normal download rate. The modem’s result is much faster, so the limitation is probably between the modem and your PC.
The provider’s modem test only proves that the modem-to-provider connection is working at the expected rate. Your own speed test also depends on the Ethernet link, router, network adapter, and the selected test server. Since the result is almost exactly 100 Mbps, look for a 100 Mbps bottleneck rather than assuming the full 1.5 Gbps is reaching the PC.
You can try basic network resets such as disconnecting and reconnecting the Ethernet cable, renewing the IP address, and flushing the DNS cache. If the adapter still negotiates at exactly 100 Mbps after checking the cable, ports, drivers, and router settings, ask the provider to troubleshoot the equipment or arrange an on-site check.
Check the Ethernet link speed on your computer. If it says 100 Mbps instead of 1.0 Gbps or higher, something in the connection is negotiating at Fast Ethernet speed. Possible causes include a damaged cable or connector, an older router, switch, hub, or network adapter, or a network-card setting. Cat5e or better should normally support gigabit over reasonable cable lengths.
That makes the cable less suspicious, but the Ethernet port or another device in the network path could still be limited to 100 Mbps. Check the negotiated speed directly in your computer’s adapter status and try connecting straight to the modem if possible.
The cable is the same one that reached around 40–50 MB/s at my friend’s house, so I’m unsure why it would be limited here.