Monday, February 23, 2009

Alfa AWUS036EH vs. Gsky 500mw USB adapter

And now begins our second round of Alfa vs. Gsky wireless testing. After we posted this comparison of the Alfa 500mw adapter vs. a Gsky 500mw adapter a few weeks ago, we have been getting a number of requests for more tests. Several readers asked how the Alfa 300mw adapter (model AWUS036EH) stacked up against the Gsky 500mw adapter (since the Gsky did not come out as well as the Alfa 500mw adapter). For full results in PDF format, including images, click here.

To summarize what's in the PDF file, the Alfa 300mw adapter performed slightly better in terms of range and signal strength. The difference was nowhere near as great as it was with the Alfa 500mw adapter in our previous test. This time the Gsky came fairly close. How is this possible considering the Gsky adapter has 500mw of output compared to 300mw for the Alfa AWUS036EH? The answer is two-fold. First, 300 and 500 are the respective numbers of the maximum output for each adapter. In most environments with most antennas, adapters will not be operating at their maximum output power. While the output power does make a difference, one thing often overlooked is chipset. The Alfa 300mw adapter has the same Realtek chipset as the Alfa 500mw adapter. The Gsky uses a less-sensitive version of a Realtek chipset.

Let's take a look at the sensitivity numbers. In this case, the Alfa 300mw adapter has the following receive sensitivity (the numbers recorded are negative, so in this case the lower the better, as such, -90 means greater sensitivity than -80):

11 mbps -86 dBm at 8% packet size
54 mbps -68 dBm at 10%

The numbers for the Gsky are:

11 mbps -82 dBm at 8%
54 mbps -65 dBm at 10%

The Alfa 300mw has the edge at both transmission rates, though the margin is not as great as it was between the Alfa 500mw and the Gsky. At the time of this writing, when factoring in shipping options the Alfa 300mw adapter is about $5.00 less than the Gsky.


Moktarino said...

Gsky may have updated the chipset to 8187L:

I just purchased this one and will verify if you'd like.

Battousai said...

Yes Moktarino Gsky has updated their chipset to Realtek 8187L but they use a "B" version of the chip serial (87e25q1) whilst alfa uses the realtek 8187L "A" version with serial (87d70a1).

I have tested many times and alfa blows gsky out of the water everytime...