I built a new PC with a Gigabyte B850 Aorus Elite WiFi7 motherboard and installed the drivers. Using the same Ethernet cable that reached gigabit speeds on my old computer, this new system only manages around 10 Mbps. Windows shows that the connection is using Ethernet rather than Wi-Fi, and the network settings report an aggregated link speed of 2500/2500 Mbps. What could be causing the slow download speed?
4 Answers
Since Windows reports a 2500/2500 Mbps link, the cable and physical Ethernet negotiation appear to be working. Check for background downloads, cloud syncing, updates, or another process using most of the available bandwidth.
Double-check that the motherboard’s Realtek LAN driver is installed correctly. If you already installed the newest version, try the previous driver release in case the current one is causing a performance problem.
Make sure the system is actually routing traffic through Ethernet. Windows should show Ethernet as the active connection, not Wi-Fi. In this case, the reported 2500/2500 Mbps link speed confirms Ethernet is active, so the driver or Windows networking configuration is more likely than the cable itself.
As a troubleshooting step, open an administrator Command Prompt and run `netsh interface tcp show global`. If TCP receive-window autotuning is set to `normal`, try `netsh int tcp set global autotuninglevel=disabled`; if it is disabled, switch it back to `normal`. This is not the most likely fix, but it has resolved similar cases.
The Ethernet driver is installed, but I’ll try rolling back to the previous version.