A New Driver for Realtek RTL8111
Due to the lack of an OS X driver that makes use of the advanced features of the Realtek RTL81111/8168 series I started a new project with the aim to create a state of the art driver that gets the most out of those NICs which can be found on virtually any cheap board on the market today. Based on Realtek's Linux driver (version 8.035.0) I have written a driver that is optimized for performance while making efficient use of system resources and keeping the CPU usage down under heavy load.
Key Features of the Driver
- Supports Realtek RTL8111/8168 B/C/D/E/F/G found on recent boards.
- Support for multisegment packets relieving the network stack of unnecessary copy operations when assembling packets for transmission.
- No-copy receive and transmit. Only small packets are copied on reception because creating a copy is more efficient than allocating a new buffer.
- TCP, UDP and IPv4 checksum offload (receive and transmit).
- TCP segmentation offload under IPv4.
- Support for TCP/IPv6 and UDP/IPv6 checksum offload.
- Fully optimized for Mountain Lion (64bit architecture) but should work with Lion too. As of now there is no support for Snow Leopard but it can be added if someone will create the necessary patches.
- Supports Wake on LAN.
- Support for Energy Efficient Ethernet (EEE) which can be disabled by setting enableEEE to NO in the drivers Info.plist without rebuild. The default is YES.
- The driver is published under GPLv2.
- As checksum offload doesn't work with jumbo frames they are currently unsupported and will probably never be.
- No support for 32bit kernels.
Before you install the driver you have to remove any installed driver for RTL8111/8168.
- Goto /S/L/E and delete the old driver (Lnx2mac, AppleRealtekRTL8169, etc.).
- Recreate the kernel cache.
- Open System Preferences and delete the corresponding network interface, e. g. en0. If you forget this step you might experience strange problems with certain Apple domains, iTunes and iCloud later.
- Install the new driver and recreate the kernel cache.
- Open System Preferences again, select Network and check if the new network interface has been created automatically or create it manually now.
- Configure the interface.
- Make sure you have followed the installation instructions especially when you have issues with certain domains while the others are working fine.
- Use the debug version to collect log data when trying to track down problems. The log messages can be found in /var/log/system.log. Include the log data when asking for support or giving feedback. I'm an engineer, not a clairvoyant.
- Check your BIOS settings. You might want to disable Network Boot and the UEFI Network Stack as these can interfere with the driver.
- Double check that you have removed any other Realtek kext from your system because they could prevent the driver from working properly.
- Verify your bootloader configuration, in particular the kernel flags. Avoid using npci=0x2000 or npci=0x3000.
- In Terminal run netstat -s in order to display network statistics. Carefully examine the data for any unusual activity like a high number of packets with bad IP header checksums, etc.
- In case auto-configuration of the link layer connection doesn't work it might be necessary to select the medium manually in System Preferences under Network for the interface.
- Use Wireshark to create a packet dump in order to collect diagnostic information.
- Keep in mind that there are many manufacturers of network equipment. Although Ethernet is an IEEE standard different implementations may show different behavior causing incompatibilities. In case you are having trouble try a different switch or a different cable.
- The driver has been successfully tested under 10.8.x and 10.9 with the B, C, D, E, F and G versions of the RTL8111/8168 and is known to work stable on these devices.
- Version 1.0.1 (2013-03-31):
- Improved behavior when rx checksum offload isn't working properly.
- Adds the chipset's model name to IORegistry so that it will show up in System Profiler.
- Version 1.0.2 (2013-04-22):
- Added support for rx checksum offload of TCP and UDP over IPv6.
- Version 1.0.3 (2013-04-25):
- The issue after a reboot from Windows has been eliminated.
- Version 1.0.4 (2013-05-04)
- Moved setLinkStatus(kIONetworkLinkValid) from start() to enable(). Cleaned up getDescCommand().
- Version 1.1.0 (2013-06-08)
- Support for TCP/IPv6 and UDP/IPv6 checksum offload added (can be disabled in Info.plist).
- Maximum size of the scatter-gather-list has been increased from 24 to 40 segments to resolve performance issues with TSO4 when offloading large packets which are highly fragmented.
- TSO4 can be disabled in Info.plist without rebuild.
- Statistics gathering has been improved to deliver more detailed information (resource shortages, transmitter resets, transmitter interrupt count).
- The interrupt mitigate settings has been changed to improve performance with SMB and to reduce CPU load.
- Configuration option added to allow for user defined interrupt mitigate settings without rebuild.
- Version 1.1.2 (2013-08-03):
- Improved SMB performance in certain configurations.
- Faster browsing of large shares.
- There are still performance problems with regard to SMB in certain configurations. My tests indicate that Apple's Broadcom driver shows the same behavior with those configurations. Obviously it's a more general problem that is not limited to my driver.
- WoL does not work in certain configurations.
Getting the driver
- The source code can be found here: https://github.com/M...driver_for_OS_X
- There is also a pre-build binary for Mountain Lion and Mavericks: http://www.insanelym...n-and-wireless/
I'm currently preparing an update which includes support for a number of newer RTL8111 family members (RTL8111GU, RTL8111EP and RTL8411B) and hopefully will eliminate some problems of older releases. Experienced users who are willing to test the new code and provide feedback can find latest sources including prebuilt binaries here: http://www.insanelym...8111/?p=2010095
Building from Source
I'm using XCode 4.6.2 for development. You can get a free copy of XCode after becoming a member of the Apple developer program. The free membership is sufficient in order to get access to development tools and documentation.