I'm having a frustrating issue with my PC where, regardless of whether I use Ethernet or WiFi, file transfers over LAN won't exceed 30 megabytes per second. For context, my WAN speed is showing 110 megabytes per second. I've ruled out several potential causes:
- The cables aren't faulty since I'm getting gigabit download speeds from outside my network.
- The router and target devices aren't the problem since other computers on the network transfer files at gigabit speeds.
- It's not a hardware issue because another Windows boot drive from the same PC can transfer at gigabit speeds.
- I've tried both the automatically selected drivers from Windows and the latest Realtek drivers, but the issue persists, and uninstalling drivers only fixed it on a different boot drive.
- I've also reset my network settings in Windows and can't find any other software affecting my network performance.
At this point, I'm stumped and could really use some suggestions on what to check next!
3 Answers
What kind of files are you transferring? If you’re dealing with large files, sometimes the write speed of your destination drive can limit transfer speeds, so it's worth checking that too!
Keep in mind that just because your WAN supports high speeds, it doesn't mean your LAN automatically does too. Check if your router and devices support WiFi 6E or WiFi 7 for maximum performance. Sometimes routers advertise total speeds rather than guaranteed speeds per device. Also, double-check that you're using at least Cat5e cables and try swapping ports on the router to see if it makes a difference!
I'm certain it’s not the cables – I’ve used multiple Cat5e cables that work fine at 1000 Mbit on other devices. They also show 1000 Mbit speeds in Windows. It's only a local transfer issue since the exact same PC performs at 1000 Mbit on a different boot drive. And it caps at 30 MB/s on WiFi too, even though it goes over 110 MB/s on WAN!
Sounds like it could be a driver issue. Have you tried uninstalling the current driver, removing the device from the Device Manager, and then rebooting your PC? After that, update the driver again. Sometimes a fresh start can clear up weird issues like this!
Great suggestion! That actually worked for me on another boot drive, but oddly enough, it's not fixing this issue. It’s strange since it happens over both WiFi and Ethernet, so I figured it wouldn't just be a driver problem since those are different drivers.
I’ve tested different file types, like MKV, MP4, ZIP, and EXE – all capped at 30 MB/s on both Ethernet and WiFi. But those same files transfer at 110 MB/s using a different Windows boot drive!