I've just built a new PC and I'm experiencing some strange issues with my Ethernet connection. To elaborate, speed tests show good results, but when I try to use certain websites like Facebook, they load very slowly or not at all. Conversely, my WiFi connection runs smoothly even though download speeds for larger files on WiFi from Steam are slower.
Here are my specs:
- Motherboard: ASUS PRIME Z890-P WIFI
- RAM: G.Skill AEGIS DDR5-6000 - 16GB - CL36 (I know it's in single channel, but RAM prices are pretty high right now)
- CPU: Intel Core Ultra 5 245KF
I've tried a bunch of fixes without success:
- Used different drives on both WiFi and Ethernet, but there was no difference.
- Sent my motherboard back for a replacement, still the same issue.
- Tested different browsers including Google Chrome, Edge, and Firefox with no change.
- Restarted my router but saw no improvement. My laptop runs Windows fine on WiFi (though it doesn't have an Ethernet port).
Interestingly, when I installed an older version of Windows 11 (21H2), everything worked properly. This makes me think it might be a software issue with the latest version. I've also tried disabling Receive Window Auto-Tuning in the command prompt, but I'm still stuck. I really don't want to rely on WiFi for larger downloads; I want my Ethernet to perform as expected. Any suggestions on what I might try next?
3 Answers
I had a similar issue with my setup and it turned out to be a faulty Ethernet cable. I switched to a new Cat6 cable, and it made a huge difference. If you haven’t already, you might want to try that!
Consider checking for packet fragmentation on your Ethernet connection. You might want to lower your MTU if you're facing issues at the default 1500 setting. It could help with the slow website loading.
Have you tried updating the Ethernet drivers from your motherboard's manufacturer? Sometimes, Windows doesn’t provide the latest versions, and that can lead to weird networking issues. It’s worth a shot!
I've tested all drivers directly from the manufacturer's webpage, but I appreciate the suggestion!

All my cables are Cat6, so I don't think that's the issue. Thanks for the tip though!