Releases: Mieze/LucyRTL8125Ethernet
Version 1.2.0d5
Here is version 1.2.0d5 of LucyRTL8125Ethernet which brings several important changes:
- Added support for AppleVTD (not required, also works fine with AppleVTD disabled).
- Implemented an interrupt throttling algorithm to reduce CPU load and improve throughput as the hardware interrupt throttling function is broken in the RTL8125.
- Limited jumbo frame support (MTU <= 4076) due to hardware issues and limitations of AppleVTD.
Just a few more words on jumbo frame support which has turned out to be problematic. Unlike the RTL8111, the RTL8125 only works reliable, when receive buffers are large enough to hold an entire packet as spreading a received packet over more than one buffer might cause trouble. Unfortunately there is no reliable way to get a physically contiguous packet buffer which is larger than 4096 Bytes (one page) under macOS, in particular with AppleVTD enabled. Therefore I had to limit jumbo frame support to a maximum supported MTU of 4076 (4096 - 20 = 4076).
Monterey and below:
Due to a peculiarity of the network control panel in System Preferences, it is not possible to set an MTU greater than 1500 if the driver doesn't report a maximum supported packet size of at least 9018 Bytes. As reporting the correct maximum packet would effectively disable the ability to use jumbo frames at all, LucyRTL8125Ethernet reports a maximum supported packet size of 9018 Bytes (MTU = packet size - 18) but any attempt to set a MTU over 4076 will fail. Please keep that in mind when you are planning to use jumbo frames. Yeah, I know this is an ugly workaround but the only solution to enable jumbo frames at all.
Ventura and above:
LucyRTL8125Ethernet will correctly report the maximum supported value for MTU as 4076 as the behaviour of the network control panel in System Preferences has been changed.