Asus RT-N66U Dark Knight Double 450Mbps N Router review: Asus RT-N66U Dark Knight Double 450Mbps N Router

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The Good The true dual-band Asus RT-N66U Dark Knight Double 450Mbps N Router offers excellent coverage, stable wireless signals, and stellar data rates on the 5GHz band. The router comes with a generous feature set and can also work as a standalone VPN server.

The Bad The RT-N66U's firmware is a little buggy and its data rate on the 2.4GHz band could use some improvement. The router's USB ports don't support the USB 3.0 standard.

The Bottom Line Though not perfect, the Asus RT-N66U Dark Knight Double 450Mbps N Router would make an excellent network gateway for home and small-office environments.

8.3 Overall
  • Setup 8
  • Features 9
  • Performance 8

I've held off reviewing the Asus RT-N66U Dark Knight Double 450Mbps N Router until now due to some known bugs in earlier versions of its firmware. The latest, version, is still, well, a little buggy, but fortunately not seriously enough to keep the router from being an excellent networking device.

Being the first N900 router from Asus, the RT-N66U offers stellar performance on the 5GHz band and a vast number of features. The router also has great wireless range and was very stable in my testing. With two USB ports it has more to offer than other USB-enabled routers, and it was very fast when coupled with a storage device.

The RT-N66U isn't perfect, however. Performance on the 2.4GHz band was slower than I expected, and the router's USB ports lack support for the latest USB 3.0 standard. Nonetheless, if you're looking for a top-notch router for your home or even a small office, the RT-N66U is one of the best on the market, especially considering that its street price is lower than that of the Linksys E4200v2 from Cisco.

Design and ease of use
The RT-N66U looks similar to its predecessor, the RT-N56U, with a sleek casing that more resembles a jewelry box than a networking device. The RT-N66U, however, can't disguise its true nature due the external-antenna design, with three of them sticking up from the back. These antennas are detachable but you do need them in place for the router to work.

Also on the back, you'll find four LAN ports and one WAN port. All of these ports are Gigabit Ethernet, meaning you'll also be able to get a fast wired network if you're not interested in wireless. Near these ports are the Wi-Fi Protected Setup (WPS) button, the reset button, two USB 2.0 ports, the power button, and a tiny power port. While that may seem to be a lot of things on the router's back, items are well-distributed, so it's less cluttered than you would imagine. Still, it would be a lot better if a few items were moved to the front or the sides of the router, where there are no buttons at all.

On the front, the router has an array of LED lights that show the statuses of the ports on the back, the connection to the Internet, the USB ports, and the wireless networks.

The RT-N66U comes with four rubber feet to make it stay put on a surface, but it's also wall-mountable. It comes with a separate base -- which, interestingly, I couldn't attach to the router until I broke a little piece of plastic off of it -- for keeping it in a vertical position. (That little piece is probably there to keep the base from falling off, but it's just too long, making it almost impossible to attach the base to the router.)

The router comes with a CD that contains setup software that walks you though every single step of how to set it up, so it should be very easy for home users. Savvy users can skip the CD and use the router's Web interface to set it up by pointing a connected computer's browser to, which is the router's default IP address. The first time you go there, the interface will greet you with a Web-based wizard with steps similar to those of the desktop setup software.

Either way, you won't have any problem getting the router up and running. I myself was able to do that in less than 10 minutes, including opening the box.

The RT-N66U is an N900 true dual-band router, meaning that both of its bands (5GHz and 2.4GHz) can offer up to 450Mbps, currently the fastest speed of the Wireless-N standard. In order to enjoy this higher speed, your Wi-Fi client also has to support the 450Mbps standard (also known as the 3x3 standard), which most of them don't. Nonetheless, the router works with all existing Wi-Fi clients, including those made for pre-N wireless standards.

To make sure the router offers maximum compatibility, you'll need to change the settings of its wireless networks to Auto and the encryption methods to support both AES and TKIP methods. To do this you will need to use the Web interface, which also allows you to access to all of the router's features.

And the RT-N66U's Web interface is great: well-organized, responsive, and reasonably simple. There are three major parts of the interface that you can access from the left part of the page. The top part is the setup wizard mentioned above, the middle is for General items, and the bottom is the Advanced Settings.

General offers a Network Map for viewing currently connected devices, including those connected to the router via the USB ports. You can click on one of the connected devices to interact with it. For example, you can quickly block a Wi-Fi client or set up a network storage feature of an external hard drive. In the General area, you can also add or change up to six Guest networks, three for each band. Other nifty General features include a Parental Control feature, a Traffic Manager, and management of the router's USB ports.

The USB ports can be used for a lot of functions. As with most USB-enabled routers, you can connect USB external storage devices or printers to these ports and turn the router into a storage or print server, both of which by the way worked well and were easy to set up. With the RT-N66U, these ports can also be used to host storage over the Internet, coupled with a cellular USB dongle so the router can work as a mobile hot spot, and when an external hard drive is connected you can also use the router to manage downloads by itself. The router's PC-less download feature supports FTP/HTTP downloading, BitTorrent, NZB, and eMule and worked well in my trials, except the fact that it doesn't support downloads from sites that require authentication.

Lastly, the Advanced Settings offer more in-depth access to the router's features, some that would be specifically useful for businesses. The most notable feature is the VPN server for creating a secure virtual private network for remote users. You do need to possess decent networking know-how to set up and manage a VPN. The router also supports IPv6, a customizable firewall, and QoS.

Overall the RT-N66U offers most, if not all, of the features you might want from a high-end router, and all the ones I tried out worked very well. I did find a few small bugs, however. For example, via the Web interface you can set the router to automatically check for and update itself with the latest firmware. The problem is this function always says that there's a new firmware version available even when the router has been updated with the latest. For this reason, you'll need to check Asus' support Web site to find out if there's actually a new version of the firmware available.

The RT-N66U offered stellar performance on the 5GHz band. For the throughput test, which was done at a close (15 feet) distance, when used with 450Mbps clients, it scored about 182Mbps. At this speed, the router can finish transmitting 500MB of data in about 20 seconds. When I increased the distance to 100 feet for the range test, still with a 450Mbps client, the router managed to maintain a high throughput of about 155Mbps.

I also tested the RT-N66U with regular 2x2 (300Mbps) clients and on the 5GHz band and it scored an impressive 110Mbps and 98Mbps for close and long distances, respectively.

It was quite a different story when I moved to the popular 2.4GHz band, however. In this band, the RT-N66U, though not slow, wasn't able to impress me. When used with 450Mbps clients, it scored 55Mbps and 45Mbps for close and long distances, respectively. With regular clients, speeds were reduced to just 37Mbps and 29Mbps.

To make up for this, the RT-N66U offers very long range on both bands, up to 300 feet in my testing. It was also very stable and passed my 48-hour stress test with no problems. During the stress test, the router was set to continuously copy data back and forth between multiple clients, both wireless and wired. Neither of the router's wireless bands disconnected once during this time.

Despite the fact that the RT-N66U doesn't support USB 3.0, its network storage performance was also very impressive, with 132Mbps for writing and 88Mbps for reading over a Gigabit Ethernet connection. These speeds are fast enough for light media streaming and data sharing. The only router that was faster than the RT-N66U in this category is the Linksys E4200v2 from Cisco, which has fewer features than what the RT-N66U has to offer.

NAS write test (in Mbps)

(Longer bars indicate better performance)



Cisco Linksys E4200v2



Apple Time Capsule


Netgear WNDR4500


Cisco Linksys E4200


Cisco Linksys E3000


Netgear WNDR4000


D-Link Xtreme N Storage Router DIR-685


Netgear WNDR3800


Cisco Linksys E3200


Netgear WNDR3700


5GHz Wireless-N performance (in Mbps)

(Longer bars indicate better performance)



Cisco Linksys E4200v2 (with 450Mbps clients)

Asus RT-N66U (with 450Mbps clients)


Belkin N750 DB (with 450Mbps clients)


Netgear WNDR4500 (with 450Mbps clients)


Cisco Linksys E4200v2


Trendnet TEW-692GR (with 450Mbps clients)


Asus RT-N56U


Asus RT-N66U


Netgear WNDR4500

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