Network Speed Problems

Hi There

I posted awhile ago with the same sort of problem, That being i have an Asustor AS-U2.5G2 USB adaptor that when i connect it to my Dell XPS running manjaro and my Surface Laptop Go running Pop OS! the speeds when im copying files to my laptops are just garbage on my Dell i get about 60MBps and bout 25MBps on my Surface. I was asked to run ethtool to check to see what link spend it was connecting at so below i have provided the info.

ethtool enx00e04c68050d
Settings for enx00e04c68050d:
Supported ports: [ ]
Supported link modes: Not reported
Supported pause frame use: No
Supports auto-negotiation: No
Supported FEC modes: Not reported
Advertised link modes: Not reported
Advertised pause frame use: No
Advertised auto-negotiation: No
Advertised FEC modes: Not reported
Speed: 2500Mb/s
Duplex: Half
Auto-negotiation: off
Port: Twisted Pair
Transceiver: internal
MDI-X: Unknown
netlink error: Operation not permitted
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes

My server im pulling files from and uploading to is a Truenas Core system with dual Intel 10gig nics, the switch im connecting to is 10/5/2.5/1gig port.
On Windows 10 using my Dell i can get 280+ MBps but not even close on Manjaro or Pop OS!.
It says it uses the RTL8156B controller so could it just be the driver is shit on Linux?
I also have a different 1gig usb ethernet adaptor and get basically the same speeds as the 2.5gig adaptor on Linux but was able to get 113mbps on Windows 10.

Anyone have any ideas or could offer some help?


  1. Check/replace the cable(s)
  2. If you think your cables are OK because whatever reason (e.g., worked before, i don’t want to replace), see step 1. Can’t overstate the circles i’ve previously gone around with dodgy cables.
  3. Maybe its the driver?

Half duplex - something is screwy, my bet with your cable(s).

If your cable is only cat5 or cat5e - i’m not sure they’re rated for >1G and whether it works or not could be borderline depending on the NIC it is attached to.

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