USB-C Ethernet unreliable

[rajs]

As far as the analysis is concerned, some of the key observations are:

- Belkin Adapter: The reduction in download / upload speeds between connecting the ethernet cable directly to the MacBook versus connecting the ethernet cable to the [ ... ] MacBook is real. The speed reduction averaged 295 Mbps / 190 Mbps ...
...
... use the Realtek 8153 chip and the com.apple.DriverKit.AppleUserECm driver. The other adapters use the Realtek 8156 chip and the com.apple.driver.usb.cdc.ncm driver (with this also being the driver that the ASD uses!). Whether one or both of these differs explains the speed reduction is for others to answer (i.e., it is beyond my capability)...

re: Realtek 8153 (gigabit) and 8156b ethernet controller Chipsets (2.5 gigabit) one of them by default MacOS has drivers for supporting off loading from CPU (8156) and for the other it doesn't (8153). In general -- get 8156 chipset based USB ethernet dongle if you have a M1 type CPU.

FYI:
ECM driver is -- CPU loading (8153 chip based USB Ethernet controllers)
NCM driver is off load type (8156 chip based USB Ethernet controllers) (PREFERRED)

More info and details on how to see which driver type you running, which chipset your USB Ethernet controller has, what speeds you are getting and how to test it properly is at this link: https://gist.github.com/MadLittleMo...malink_comment_id=4029252#gistcomment-4029252

For more details on Macrumors search for my user name and the ethernet. I've posted on this topic in past when I ran into the problem initially using a Macbook Pro (m1Pro) in 2021. I've been rock solid since sticking with using 8156 chipset based USB Ethernet controllers. Zero disconnects, zero loss packets, zero issues on a Macbook Pro that stays 24x7x365 turn on except for time between system update reboots and/or time I am traveling with the laptop.

Best of luck.

ps: STRONGLY recommend you do NOT install an externally sourced driver for your ethernet (what ever speed type). Stick with the drivers that ship natively from Apple and are included on every release and update for MacOS. You really don't want to be installed drivers that you've downloaded from the internet, even if it's from a "manufacturer" website for overall system integrity / security purposes. .

 

[haralds]

I noticed my U-Green 2.5Gbps adapter would only run in 1Gbps mode in its automatic setting. I had to manually set it to 2.5Gbps mode. It did show high loading in Speedtest. But on my M1 PowerBooks 13", WiFi also showed a pretty high load. only offloading the efficiency cores when running on WiFi. That achieved less than half the speed over my Eero 7 about 8ft from the router. Apple WiFi performance is poor.

 

[jollino]

re: Realtek 8153 (gigabit) and 8156b ethernet controller Chipsets (2.5 gigabit) one of them by default MacOS has drivers for supporting off loading from CPU (8156) and for the other it doesn't (8153). In general -- get 8156 chipset based USB ethernet dongle if you have a M1 type CPU.

FYI:
ECM driver is -- CPU loading (8153 chip based USB Ethernet controllers)
NCM driver is off load type (8156 chip based USB Ethernet controllers) (PREFERRED)

Rajs, I read a big chunk of the Github discussion as well, but I'm a little confused as to how it applies here. I have an 8156 that correctly uses the default NCM driver (thanks for the clarification on the difference, by the way!), but the issue we're facing is that the very same hardware used to saturate the 2.5 GbE link, and now only gets a little less than 2.0 Gb. With everything being the same — Mac, adapter, cable, router, ISP... — we've lost 20% of the speed.

Even more confusing, it seems to be somehow capped only for inbound traffic. I posted logs at https://forums.macrumors.com/threads/usb-c-ethernet-unreliable.2287743/post-33627808 and @msncookie at https://forums.macrumors.com/thread...since-upgrading-to-15-0.2437227/post-33677226 confirmed the same findings. I wonder if others would be able to try the same. I cannot test 2.5 upload over the WAN because my ISP gives me 500 Mbps up, but over the LAN I definitely get 2.5 Gbps out and only 1.9 Gbps in.

I have no idea if Sequoia has some kind of filtering happening on inbound traffic that can't be disabled, or the driver itself became less efficient. It's definitely not an issue of ECM vs. NCM as all 8156 chips are NCM, and all 2.5 GbE adapters are 8156 (please correct me if I'm mistaken).

Some have had success with 5 GbE adapters based on the 8157, but someone posted somewhere that even that exhibits some loss when using an actual 5 Gbps link; it's just that there's a lot of headroom with them when the links only 2.5 Gbps, just like using a 1 Gbps link on a 8156 shows no difference between Sequoia and Sonoma.

It's not a big deal in most cases, obviously, but it's frustrating that Apple just broke something that literally worked perfectly and, after three Sequoia updates, we're still dealing with this.

 

[skiabox]

After nearly 3 months of usage I can confirm that D-Link DUB E-250 2.5 Gbps adapter is still working fine without any problems!

 

[jollino]

If anyone's wondering 15.3.1 changes nothing. Still full speed when sending, and 1.9 Gbps when receiving (with many TCP retries marked by iperf3 only when receiving).

@skiabox, would you mind sharing what System Profiler reports about your D-Link in the Ethernet tab, please? I'm curious to see how it differs from others 8156-based adapters, maybe we can figure out some pattern.