Especially, if you don't want to sacrifice that precious Thunderbolt port or rely on Apple's 10/100 ethernet USB dongle? Well, any pretty much any ASIX AX88179 Chipset USB 3.0 to Gigabit adapter will work. There are scores of them on Amazon, Ebay and NewEgg.
They come in different colors, different packaging from different manufactures. However, they all have pretty much the same guts. A while back, I reported having a DOA, bad experience with an Anker USB 3.0 Gigabit adapter. Today, I am reporting better luck with a NewEgg Rosewill adapter using the same ASIX AX88179 chipset.
I recently picked up a few for $17 on sale (regularly $28) at Newegg.
The RNG-406U is a standard, sturdy dongle. In fact, it looks more attractive than the Anker that failed me prior.
After opening the box, I quickly loaded up the latest driver from ASIX's website and got my Gigabit speeds. I tested under Mountain Lion 10.8.2 and it works as advertised. I also have the white Apple USB 2 10/100 ethernet dongle and that thing is pretty slow. Under testing, the Rosewill Gigabit adapter was hitting 117 MB/sec using iperf so I am definitely hitting Gigabit's maximum theoretical limit (of 125 MB/sec). In fact, it was just as fast as the internal gigabit on my Macbook.
I even plugged it into my Thinkpad T420 running Ubuntu via a USB 3.0 expresscard and was able to make install the drivers easily. I can confirm it works pretty good under Unbutu 12.04 after installing the kernel drivers. So far, so good. A USB gigabit dongle that works on multiple platforms. I ended up buying three more to leave at different locations. I'm always developing server apps and usually need a few network ports for testing.
One big major issue. Of course, I wouldn't do you guys a service if I didn't acknowledge one glaring issue.
The main issue with this dongle (that I will show how to easily resolve) is the fact, you need to have it plugged in at boot.
If you unplug and replug later, it will not work again. If your machine is already booted or just recovered from sleep, the dongle will not work. The operating system will recognize the dongle but no connection. I usually never shut down or reboot my mac. If I am transporting from home and work, my machine usually just goes to deep sleep. Hence. this was an issue I wanted to resolve.
Now, under most circumstances a simple command line: sudo ifconfig enX down and ifconfig enX up cures all the problems. However, simply restarting the network interface does not work.
To solve this problem, simply unload and reload the kernel kext file (OSX driver). It is located in the plugin folder of the IONetworkingFamily inside System/Library Extensions.
To unload, type in the terminal :
sudo kextunload /System/Library/Extensions/IONetworkingFamily.kext/Contents/PlugIns/AX88179_178A.kext
Then to reload, type in the terminal:
sudo kextload /System/Library/Extensions/IONetworkingFamily.kext/Contents/PlugIns/AX88179_178A.kext
This will fix it. Simple isn't it? I just make a .bash script and leave it in my home directory and drag-n-drop it into the terminal to run. Voila, working dongle again.
There you have it. A cheap USB 3.0 Gigabit solution. I've even seen a few ASIX AX88179 dongles that are built in 4-5 port hubs. I may try that next.