Excellent QoS features; SD card reader; dual USB 3.0 ports.
Relatively short range, especially on the 5GHz band; slow write-to-NAS speed.
In case you’re wondering why we’re reviewing an 802.11n router when the first 802.11ac routers have already reached the market, we have several reasons. First and foremost, the latter didn’t make it to the Lab in time for our print deadline. Secondly, the IEEE isn’t expected to formally ratify the 802.11ac standard until early 2013. The 802.11ac routers on the market today are based on Draft 2.0 of the standard, so there’s a remote chance they could be rendered obsolete when the standard is finalized.
D-Link has been oddly quiet about its plans for 802.11ac, but we’re guessing the DIR-857 will likely be the company’s last consumer-oriented 802.11n model. The DIR-857 is housed in the same low-profile enclosure as the less-expensive DIR-827 we reviewed in May 2012, with a 3x3 antenna array hidden inside and just two discrete status LEDs on top. We understand the “spouse acceptance factor,” which requires consumer electronics hardware to be designed to disappear into a home’s décor in order to be acceptable to your non-geek significant other, but a flat router with internal antennas just isn’t going to perform as well as a vertical model even if they both have internal antennas. Pit one of those against any model with external antennas, such as the Asus RT-N66U, and it will fare even more poorly.
Yes, there are 802.11ac routers on the market, but they’re based on Draft 2.0 of the standard, and the Wi-Fi Alliance did not have a certification program in place at press time.
That’s certainly what we found when we compared the DIR-857 to the RT-N66U: The Asus router, with its semi-vertical orientation and its positional external antennas, crushed the D-Link both in terms of wireless throughput and range. When the client was set up in our acoustically isolated home theater, the RT-N66U delivered more than three times as much throughput, guaranteeing that we’d be able to stream high-definition video to our HDTV without wires. And where the D-Link was barely able to reach the client at our outdoor location, 85 feet from the router, the Asus delivered enough throughput that we’d have no trouble streaming HD video there, too (at least on the 2.4GHz band. The RT-N66U’s throughput dropped to 3.9Mb/s on the 5GHz band, but the DIR-857 wasn’t able to connect at that location at all at 5GHz).
Since media streaming is such an important application for wireless routers, we’ve added a new test to our benchmarking suite: We mount a Blu-ray disc image on our notebook PC (from an .iso file stored on our Windows Home Server 2011 machine), and we stream that file across the wireless network. At the same time, we download a large file from the Internet to a second wireless client. Neither router had a problem fulfilling that task at a distance of 45 feet from the router, with an insulated wall, wooden cabinets, and several stainless steel appliances (a refrigerator, a built-in double oven, and a range) in the signal path.
Despite the DIR-857’s performance coming up short compared to our new zero-point, we still think it’s a very good router. It boasts a rich feature set, including two USB 3.0 ports that made for very fast NAS-to-PC file transfers (it fell far behind the RT-N66U, however, when it came to PC-to-NAS transfers), it has a handy built-in SD card reader, and—as is typical of D-Link routers—it’s equipped with excellent Quality of Service settings. It’s just not as good as Asus’s RT-N66U.
|TCP Throughput (Mb/s) ||945.0||943.0|
|PC to NAS, small (sec) ||78.3||46.0|
|PC to NAS, large (sec) ||333.0||161.7|
|NAS to PC, small (sec) ||49.7||81.3|
|NAS to PC, large (sec)||163.7||280.7|
|D-Link DIR-857 (2.4GHz Band)||AsusRT N66U(2.4GHzBand)||D-Link DIR-857 (5GHz Band)||AsusRT N66U (5GHz Band)|
|Bedroom 1, 10 feet (Mb/s)||112.0||141.0||124.0||152.0|
|Kitchen, 20 feet (Mb/s)||73.7||133.0||93.2||129.0|
|Patio, 38 feet (Mb/s)||65.3||110.0||56.7||64.1|
|Home Theater, 35 feet (Mb/s)||24.6||77.7||5.2||30.1|
|Outdoors, 85 feet (Mb/s)||2.7||50.3||N/C||3.9|
Our zero-point ultraportable is an Asus Zenbook UX31E with a 1.7GHz Intel Core i5-2557M, 4GB of DDR3/1333 RAM, integrated graphics, a 128GB SSD, and Windows 7 Professional 64-bit.