Editors' note, December 14, 2015: This review was updated to change its overall rating to reflect its position in relation to newer routers.
The AC2400 RT-AC87U Dual-band Wireless Gigabit Router is a big leap in home Wi-Fi performance. And a month after its release, it's now even better thanks to recent firmware update that squashed a round of initial bugs. It's now safe to get and I recommend it.
The new router has everything the previous model, the RT-AC68U, has to offer and then some. Yet at the same time, it manages to remain as easy and fun to use as its predecessor. You do need hardware with compatible superfast 802.11ac Wi-Fi to take advantage of its top speed, however.
In my testing, the RT-AC87U delivered the fastest Wi-Fi speed I've seen and exhibited the longest effective range, living up to its potential as the first 4x4 802.11ac router. On top of that, it also made a good NAS server when hosting an external hard drive.
On the downside, its bulky design could be improved. And at $280/AU$329 it's cost-prohibitive to many. (Pricing for the UK is not yet available, but converted it's about £170.) That said, if you live in a large house and need better Wi-Fi coverage, the RT-AC87U, is totally worth the investment.
For more affordable choices, check out this list of the top 802.11ac routers on the market.
The RT-AC87U packs an impressive punch. It's the first router on the market that supports the four-spatial-stream setup (4x4) of the 802.11ac Wi-Fi standard, using the dual-core 500MHz Quantenna QT3840BC chip. (Read more about Wi-Fi standards here.) This means on the 5GHz frequency band, it's capable of delivering the top speed of 1733Mbps when working with a 802.11ac client (such as a smartphone, tablet, or PC).
Keep in mind that while the router supports all existing Wi-Fi clients on the market (regardless of their Wi-Fi standards), in order to achieve the quad-stream speed, you also need quad-stream-enabled clients. Currently there aren't any on the market, though some are expected to be available by early next year.
On the 2.4GHz band, the router sports a dual-core 1GHz Broadcom BCM4709 chip that delivers up to 600Mbps. This chip is also used for the router's other functions, including the USB, NAT, system operation, and so on. This is a true dual-band router so it has the total combined Wi-Fi bandwidth of 2333Mbps, but Asus rounds this up to categorize it as an AC2400 router.
The Asus also has 128MB of flash memory and 256MB of DDR 3 system memory. In all, it has enough power as a small server and is currently the one with most powerful specs among home routers.
As a router, the RT-AC87U has four Gigabit LAN ports and one Gigabit WAN (Internet) port on its back. This is a normal number of network ports for a home router. The RT-AC87U is very large though and therefore has enough space for a few more LAN ports. The more ports you have, the more wired devices you can plug in before having to resort to a switch.
The router does come with two USB ports. The USB 2.0 port, as usual, is on its back, but for some reason the USB 3.0 port is placed on the front. Generally, the USB 3.0 port would be used to host a permanent storage device, and having this port on the front means you'll have a messy setup should you choose to use the router as a NAS server.
I understand the lack of extra network ports and the placement of the USB 3.0 port depends on the design of the router's main circuit board, but it's something Asus should keep in mind for its future routers.
On the front, the router comes with an array of fancy LED status lights. I found these lights very helpful but unfortunately they all face downwards. This means no matter how the router is placed (either on the floor or mounted on wall), chances are you won't be able to see these lights at all, without bending down. Since you can turn these lights on or off via a button on the router's front, the fact that they are hidden away serves no purpose at all.
Similar to recent previous 802.11ac routers from Asus, including the RT-AC66U and the RT-AC68U, the new RT-AC87U is very easy to set up. All you have to do is plug the router in and point a browser to the router's default IP address (192.168.1.1). The first time you go there, the interface will greet you with a Web-based wizard, which walks you through a few steps.
After that, you can always go back to this interface to manage the router, as well as to customize other settings and features. It's interesting to note that the RT-AC87U shares the same settings structure as previous RT-ACxxx models. I tried restoring it with the settings file of the older RT-AC68U, and it worked. This makes it very convenient for owners of Asus' older routers to upgrade to the RT-AC87U since they won't need to reprogram the new router from scratch.
The RT-AC87U shares the same robust and easy-to-use interface as previous RT routers. It also has all the features that the RT-AC68U has and more. A few common major features include:
Six guest Wi-Fi networks: The router has three guest networks for each band. By default, these are turned off but you can easy turn one on with a click. After that you can customize this network's name, as well as its security. A guest network allows connected clients to access the Internet but not other local resources, such as files or printers.
Interactive Network Map: This is a great feature 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 or view more information about it. Clients connected to the router are also sorted by the connection method, including wired, and by which wireless network they're connected to.
Multiple purpose USB ports: The router's USB ports can be used for a variety of functions. They can host external hard drives, cellular modems, or printers. When a hard drive is connected, you can share the data stored on it with local clients or remote clients over the Internet, and you can even setup sync function, native Time Machine backup support, and PC-less download function. You can do basically everything you can imagine with the router's built-in network storage feature, making it a great NAS server.
VPN support and many other advance settings: The router comes with a built-in VPN server feature that allows you to create a secure virtual private network for remote users.
On top of that it also supports Dynamic DNS, IPv6, a customizable firewall and many other features commonly found in other home routers. There's one minor caveat: while you can easily assign a fixed IP address to a connected client, once the IP is assigned, the client is now remembered by its MAC address, instead of its name. Since the MAC address is a string of numbers and letters, this makes it very hard to know which client has which IP address when you have multiple clients on the IP reservation list.
Other than that, the RT-AC87U has new Adaptive QoS (quality of service) and AiProtection features, which are not available on previous models.
Adaptive QoS prioritizes the Internet bandwidth according to the type of traffic: Web Surfing, Gaming, Video and Audio Streaming, VoIP/Instant Messaging, File Transferring, and Others. You can easily use the mouse to arrange these categories in the list of highest and lowest priority and the router will take care of the rest. On top of that, there's also a function called "apps analysis" that allows for real-time monitoring of the Internet activity of any connected client as well as the total download and upload bandwidth being used. This is a very helpful tool if you want to find out which client or application is abusing the Internet connection. What I like most about the Adaptive QoS is the fact you can still manually program QoS rules if you want to using the Traditional mode. The only drawback is the fact that the router takes about five minutes to turn Adaptive QoS on or off.
AiProtection is a new, unique security feature powered by Trend Micro, and designed to protect the entire home network against viruses and malware from the Internet. And if a client has already been infected, this feature will also stop it from sending personal information. AiProtection actually worked well in my trial, even though it's hard to say if it can protect your home network completely. What was clear to me was the fact that if you turn the protection on all the way, certain settings/features of the router that are prone to security risks, such as port-forwarding, UPnP, remote access etc., might stop working, too.
All in all, this new Asus has the most complete feature set I've seen for a home router.
Since there are virtually no 4x4 802.11ac clients on the market, I used another RT-AC87U unit in bridge mode for testing, and the router excelled with a sustained speed at close range of 1,030Mbps, the fastest I've seen before. When I increased the distance to 100 feet (30 meters), it registered 381Mbps -- still very impressive.
When used with regular 3x3 Wi-Fi clients the router also did very well, scoring 504Mbps and 279Mbps for close range and long range, respectively. These were about the average among AC1900 routers on the market.
Note that 802.11ac only works on the 5GHz frequency band. On the 2.4GHz, the RT-AC87U also did very well with 171Mbps for close range and 56Mbps for long range.
What I like the most about the new router is its Wi-Fi coverage, exhibiting the longest effective range I've seen, some 300 feet (91 meters). Effective range is the distance at which a client can connect to the Wi-Fi network and remain connected with a stable connection.
The router also passed my 48-hour stress test with no problems at all. During this time, it was set to transfer data constantly between multiple devices, both wired and wireless, and of different Wi-Fi standards, and none of the clients disconnected even once.
Note that I tested the router at CNET's offices, where there are plenty of walls and many Wi-Fi devices, including those from adjacent buildings, that are out of my control. Generally, walls shorten the reach of a Wi-Fi signal, and other Wi-Fi devices create interference. As with all Wi-Fi routers, your results may vary depending on where you live.
When coupled with a portable drive, the RT-AC87U also did well as a small NAS server. Via a Gigabit connection, it scored 27MBps for writing and 32MBps for reading. These weren't as fast as some other routers on the market, even slower than those of the RT-AC68U, but fast enough for most casual needs for data sharing, media streaming and even Time Machine backup.
Overall, with the latest firmware, the RT-AC87U worked well in my testing. The router did become rather warm after working for an hour or so, but not hot enough to be of concern. Still, as with any other router, it's recommended that you place it in an open area.
The Asus AC2400 RT-AC87U Dual-band Wireless Gigabit Router is an excellent networking device with a premium price. In the end, it boils down to whether or not you can afford it.
If you can, you'll enjoy its excellent Wi-Fi range, unique feature set, and, if you're using 802.11ac clients, its great speed. Considering the fact that there are fewer 802.11ac devices than 802.11n devices, however, it might take a few years before you'll need something like the RT-AC87U.
That said, if you're already using an 802.11ac router, there's no need to upgrade just yet. But buying it now means you're doing so to future-proof your home for a few years to come, when you'll (presumably) have more compatible devices.