Results - Fast-Lane
"Fast-Lane" technology is something found only in the NETGEAR extenders. As described above, the technology lets you use one band (and radio) to communicate from your client to the extender, and the other band (and radio) to communicate from extender to router. Since we greatly reduced the throughput we had to work with at the extender location with attenuators, the numbers for Fast-Lane may not look at all that impressive. In normal operation, you might see much better.
I set up Fast-Lane to link back to the router with the 5 GHz band and to my client with the 2.4 GHz band. We can expect that we are going to be looking at roughly the throughput that we saw for 2.4 GHz wired since it's the slower of the two. Downlink was 42 Mbps and uplink was 33 Mbps, which is about what we saw for the wired 2.4 GHz bridge throughput numbers.
Let's do a by-the-numbers comparison to the top-ranked SR20000G. For downlink, the SR20000G still just beats Fast-Lane with 46 Mbps. This ratio would correlate to the numbers I can see back to the router from my laptop with attenuators off, 2.4 GHz throughput is just over half of what I see for 5 GHz in a normal situation. The Fast-Lane 33 Mbps for uplink is the best we see for uplink however, with the SR20000G giving us 19 Mbps there.
For me, the verdict is still out on Fast-Lane, especially with the crowded 2.4 GHz spectrum. If you can extend 5 GHz and extend it well, that may be just as good as using Fast-Lane.
It's no surprise that the Amped Wireless SR20000G ranked #1 among the N600 class extenders tested. It was followed by the two NETGEARs in a tie, and then the Edimax.
Wireless Extender Ranker - N600
It's possible the reason for the Edimax' poor showing is its use of a Realtek RTL8192DR as its sole radio. Since there is no datasheet available for this device and its Realtek RTL8196CS has no radio, we initially thought the EW-7238RPD was not a concurrent dual-band product.
Edimax EW-7238RPD board
After a few back-and-forths with Edimax and manually linking it instead of using WPS, we convinced ourselves that it is indeed an N600 simultaneous dual-band extender. But since it is the only product in this roundup to use this unique device as its only radio, there could be a link to its poor showing.
On the other hand, the Amped SR20000G is the only product in the round-up with a separate processor, two radio devices, plus external amplifiers for both bands. Coincidence that the Amped performs much better than the Edimax? We think not.
Amped SR20000G board
Here is the performance summary for the top-ranked Amped Wireless SR20000G. Check the Wireless Extender Ranker for details on the other products' performance.
Amped Wireless SR20000G Performance Summary
The concept behind simultaneous dual-band extenders is intriguing. But the optimal spot for 2.4 GHz extension is unlikely to be the same as for 5 GHz. So in practical use, you may end up paying extra to get just a 5 GHz signal into your dead spot. If that's what you need, although pricier than many of the N600 class routers it will be used with, it looks like the Amped Wireless SR20000G is the one to get.