Question strange USB ethernet adapter issue on PC

[dxhcom]

I noticed my PC has much slower internet speed than my phone, and then I found a strange issue for my PC.
My PC is a DIY built computer, windows 10. It ran mostly well for many (5+) years. The mother board is MSI Gaming 5. Its ethernet port was broken, so I bought a USB 3.0 ethernet adapter, but its internet speed is slow.
Here is what I tested.

I use Google Internet Speed test as the tool. My nominal Internet speed is 300 Mbps.

1. iPhone (wifi): 300+ Mbps
2. the PC with the issue: 1) Adapter on USB 2.0 port: 150~200 Mbps, 2) Adapter on USB 3.0 Port ~50 Mbps
3. Another laptop (1 year old) with ethernet port: 1) direct plugged in the port: 300+Mbps, 2) using the same USB ethernet adapter on a USB port, 300+Mbps

It appears to me that the issue is between the adapter and the USB ports on PC (especially USB 3.0 ports), but I did not find any issue in device manager. I disabled/enable some devices, trying to update the drivers, but nothing works.

any other ideas?

Thank you!

 

[rgd1101]

test with back or front port?

 

[bill001g]

I assume you tried both the front and back ports the front ports could be a wiring issue.

Hardware issues are a huge pain, maybe the same thing that broke the ethernet broke the usb3.

With as many open slots as that motherboard has I would have gone with a internal pcie card. Most are 1x cards.

 

[dxhcom]

I assume you tried both the front and back ports the front ports could be a wiring issue.

Hardware issues are a huge pain, maybe the same thing that broke the ethernet broke the usb3.

With as many open slots as that motherboard has I would have gone with a internal pcie card. Most are 1x cards.

Thank you for the reply!
I think I will go with a pcie card.

 

[dxhcom]

test with back or front port?

I have not because my cable is fixed on the wall and difficult to reach the front of the PC case, and it is not looking nice plugged in front even it is working.... I probably go with Bill's suggestion of pcie card. Hope my old computer can hold more years.
Thank you so much!

 

[dxhcom]

I bought and installed a PCIe ethernet card. It solved the problem.
The installation process was easy, but the system won't boot initially. I had to disable network boot and onboard LAN to fix (I don't know which one fixed the issue).
Thank you for the help!