USB ethernet speed issue

What is this ?
1. My desktop's WIRED DL speed = 31 Mbps
2. My laptop's WIRELESS-N DL speed = 28 Mbps
3. My laptop's WIRED DL speed (I disconnected wifi on my laptop and used the usb/ethernet adapter from ebay) = 7 Mbps

These are test speed ?
Try speedtest.net

And more details will be needed like, Specify Laptop model, you Isp name, Country, region. etc.

If your ISP contract says is 30mb/s  well is not working like this, if this is the speed they told you the real speed it will be about 10% of their recommended speed and you are lucky if your speed is 7mb/s, is a matemathic ecuation to calculate the speed of an end user. You can give a try and call up you ISP support if you believe is this a real problem.

Is the USB-Ethernet NIC connected to a USB2 port?
Is the USB-Ethernet NIC itself USB2 or USB1.1?

The speeds I posted are the results from tests I ran on speedtest.net. As you can see from my results, my ISPs package is 30 Mb/s, which is what I am receiving in my first 3 tests (but not the fourth).

The other details are:
-Laptop model = Macbook Air (2011)
-Isp name = AT&T
-Country = USA
-region = New York City

The USB-Ethernet NIC is connected to a USB2 port. I do not know if the USB-Ethernet NIC itself is USB2 or USB1.1. It did not come with any documentation and the ebay auction page only states "Complies with USB 1.1".

What speed does windows show it is connected at?  It looks as if its connecting at 10 Mbps.

I'd say it's 1.1 then, meaning the most you'll get out of it is 12Mbps theoretical maximum, but most likely less than that.

What's the make/model of the adapter?

Also its a $4 adapter that is unbranded...so I wouldn't expect much out of it

Fact that it doesn't say USB 2.0 usually means its 1.1

So as others mentioned its theoretical max will be 12MB

I've attached some screenshots.. also:

Q: What speed does windows show it is connected at?
A: 100 Mbps (see screenshot)

Q: What's the make/model of the adapter?
A: As you can see from the screenshots posted, it appears as a generic model from Corechip Semiconductor, Inc.   There is nothing printed on the adapter itself, aside from "made in china".

Since we appear to have reached the conclusion that it's a slow adapter, what should I be searching ebay for when I am shopping for a newer, faster one?  USB 3 ethernet adapter?

Screenshots:         http://i.imgur.com/hflx0U3.png

Thank you

USB 2 can go up to 480Mbit/sec.  So USB2 or 3 will do.

That assumes that your laptop's USB port is USB2 or higher.

Does your laptop support USB 3? If so, go that route. If not, it doesn't matter whether you get 2 or 3. But also, get a card from a notable brand name. And all of the modern ethernet adapters are basically gigabit, so you might as well go ahead and get one.