My ISP promises 500 Mbps up and down. With ethernet connected directly to laptop, I consitently get 550 up and down. With ethernet connected through the TBT4-UDZ, I still get 550 up but only 375 Mbps or less download (less than 70%). Tests done with Ookla.
Why don’t I get my full download speed on eithernet through the TBT4-UDZ?
I get better download speed on my Wi-Fi 6 but worse upload.
My laptop:
Dell Latitude 5520 15.6" Touchscreen FHD
Intel Core i7-1185G7
11 th Generation
3.0 to 4.8 GHz
64 GB RAM
2TB SSD
Iris Xe Graphics
Thunderbolt 4
Windows 11 Pro
Thank you for contacting Plugable support! Sorry to hear about this issue. I’d be more than happy to assist you.
I would proactively recommend to install the newest Ethernet drivers from Realtek (the manufacturer of the RTL8156 Ethernet chipset that’s in the TBT4-UDZ) as the first step from here: https://www.realtek.com/Download/List?cate_id=585
We have seen that the Ethernet drivers that Windows 11 provides by default through Windows Update can be unstable, and that often updating to the newest drivers from Realtek may help with both stability and performance.
If updating the Realtek Ethernet drivers has not helped with the performance please let me know.
Please don’t hesitate to let us know of other questions.
Thanks again for contacting Plugable support and best wishes!