[SOLVED] Ethernet adapter capped at 100mpbs

[kcxuv]

Hi!
I have a problem with my ethernet adapter only having 100mbps speed.
I have a DNA 200mbps connection and DNA F-3890V3 cable modem. Modem has 4x 1gbit/s ethernet ports
Only my desktop is connected with a cable, other devices use wifi.
Number of connected devices is usually 3

Computer Specs:
Ryzen 5 3600
RX 590
16GB Ram
Windows 11 Pro 21H2
ASUS PRIME B450-PLUS motherboard with Realtek 8111H Gigabit LAN Controller

My problems started when i was using arch linux on my desktop pc and noticing i only have a download speed of 100mbps.
I wiped arch linux and installed windows 10 and still had the same problem.
At first the driver of the lan controller was from 2015 so i updated it with windows update but it didn't fix the problem.

Now im running windows 11 with the latest driver with the same issue. I tried two linux live os (ubuntu and puppy linux) and both had the same problem.
My phone and macbook air are able to get speeds of 185-195mbps using wifi. My hp laptop when connected with a ethernet cable is also able to get the same speeds.
I have 2x Cat6 cables and 2x Cat5e. I've tried all cables on my desktop and hp laptop. Only on the hp laptop am i able to get speeds of 185-200mbps.

 

[bill001g]

This normally is a bad cable. You should be able to check the status of the ethernet port and it will show you if it is connected at 100mbps or gbit. Sometimes you can also tell by the lights on the pc or the router.

Since you have tried multiple cables this makes it much harder. Unfortantly just because it works on one machine a bad cable might not work on another. Have 4 bad ones would be extremely rare.

You have also eliminated the other possibility of driver issues since it does this on 2 different OS. Drivers almost never cause this anyway. I guess you could check the nic settings to be sure it was set to auto but that is the default both for linux and windows.

So these leaves a bad port in the pc. You might get lucky and see a damaged wires. There is no way to actually fix a port. Lucky add in ethernet cards are pretty cheap and you can use USB3 ethernet dongles if you do not have a slot You still might want to consider buying a new cat5e cable from a quality provider. Many people use those flat ethernet cables lately which do not meet the standards for ethernet and have all kinds of problems.

 

[kcxuv]

This normally is a bad cable. You should be able to check the status of the ethernet port and it will show you if it is connected at 100mbps or gbit. Sometimes you can also tell by the lights on the pc or the router.

Since you have tried multiple cables this makes it much harder. Unfortantly just because it works on one machine a bad cable might not work on another. Have 4 bad ones would be extremely rare.

You have also eliminated the other possibility of driver issues since it does this on 2 different OS. Drivers almost never cause this anyway. I guess you could check the nic settings to be sure it was set to auto but that is the default both for linux and windows.

So these leaves a bad port in the pc. You might get lucky and see a damaged wires. There is no way to actually fix a port. Lucky add in ethernet cards are pretty cheap and you can use USB3 ethernet dongles if you do not have a slot You still might want to consider buying a new cat5e cable from a quality provider. Many people use those flat ethernet cables lately which do not meet the standards for ethernet and have all kinds of problems.

I'll try using a new cable and checking the port if its damaged. Thanks for your suggestions.