USB-to-Ethernet 1.0 review

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Although USB to Ethernet adaptors are cheap and plentiful, Mac OS X drivers are not.

License: Freeware
OS: Mac OS X
File size: 224K
Developer: Sustainable Softworks and Daniel Sumorok
Price: $0.00
Updated: 09 Nov 2006
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Although USB to Ethernet adaptors are cheap and plentiful, Mac OS X drivers are not.

USB-to-Ethernet offers you USB to Ethernet Adaptor Drivers.
There are two basic catagories of USB-To-Ethernet adaptors:
USB 1.1 devices that use a Pegasus driver.
USB 2.0 devices that use a AX8817x driver (or its successor, the AX88772).

Each disk image includes an installer for Panther or Tiger, and a "src" folder containing the corresponding xCode projects.


Download and mount the appropriate driver disk image listed above, run the corresponding installer for Panther or Tiger, and then restart your system as suggested. The Installer will ask you to authenticate so it can place the corresponding driver in "/System/Library/Extensions/" with the correct file permisions to load as a kernel extension.

Next, plug-in your Ethernet adaptor with a live Ethernet cable attached. When you open the Network Preferences panel, it should inform you that a new port has appeared and ask if you want to enable it. Enable the new port and apply your network settings. That's it.

Each driver is pre-configured to recognize a handfull of common devices. If your device does not appear to be recognized by the driver, you might have to add it to the Info.plist file, which is located inside the USBPegasusEthernet.kext or USBAx8817x.kext directory. You can use the System Profiler or USBProber tool to find the corresponding Product ID and Vendor ID.

To uninstall the driver, make sure any USB adaptors are disconnected, and then drag the corresponding driver in /System/Library/Extensions/ USBPegaususEthernet.kext or USBAx8817x.kext to the trash. You may need to authenticate that you have administrator privileges.

USB 1.1 Performance

The Pegasus chipset provides a USB 1.1 compatible implementation which could be a concern for some users. USB 1.1 runs at 1.5 Mbps (low speed) or 12 Mbps (full speed). For best performance, it's important to isolate any low speed devices on a separate bus. Mice and keyboards often run at low speed.

Using the Link Rate tool in IPNetMonitorX, I measured the link rate to another device on my LAN as 6 Mbps. The built-in Ethernet on my 12" PBG4 reported 44 Mpbs. When I measured the link rate to the next hop router through my cable modem, it reported 1 mbps. It didn't make any difference whether I used Ethernet built-in or the USB-To-Ethernet adaptor. Finally, I downloaded a 2.2 MB file to compare the throughput using the Monitor tool.

Both downloads took 5 seconds, but Ethernet built-in reached a peak rate of 589 KBps versus 579 kBps. Repeating the experiment several times produced similar results. Ethernet built-in might be 1-2% faster, but performance was clearly limited by the speed of my cable modem (Your Mileage May Vary).

USB 2.0 Performance

The AX8817x chip set provides a USB 2.0 compatible implementation which runs at up to 480 Mbps (high speed), so it should be possible to keep up with 100 Mbps fast ethernet as long as there are no other slower devices on the same bus. To test this I copied a 64.8 MB music file to my PBG4 laptop connected through a LinkSys USB200M Ethernet Adaptor (en3) and compared this to the same file transfer using Built-in Ethernet (en0).

Both transfers reached 10 MBps (80-90 Mbps) and took about 10 seconds. I repeated the test in the other direction.

While the USB-To-Ethernet adaptor was slightly slower, at 80 Mbps there was little noticeable difference. Files moved quickly from one system to another via 100 Mbps fast Ethernet. Copying the same file using AirPort wireless took 50-90 seconds.


While other USB-To-Ethernet drivers are reported to be buggy, I haven't encountered any stability problems to date. The adaptor turns off when the computer goes to sleep and comes back on when the computer awakes. It does not support "Wake On LAN" at this time.

Wrap Up

This USB-To-Ethernet Adaptor combination could be an attractive solution for a Mac Mini, or old iBook used as an Internet gateway or server. I'm particularly fond of using old laptops as servers since they are compact, quiet, use little energy, and include their own battery backup.

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