The RT-AC86U is Wi-Fi Certified. It was loaded with 188.8.131.52.382_18219-g76de09e firmware and tested with the Revision 10 wireless test process . The router was reset to factory default, then set to Channel 6 for 2.4 GHz and Channel 40 and 20/40/80 MHz bandwidth for 5 GHz. WPA2/AES encryption was used for all connections.
The Revision 10 process uses 20 MHz bandwidth for 2.4 GHz tests for throughput vs. attenuation, but uses 40 MHz for peak throughput tests. These settings are enforced by the octoScope Pal test client. 2.4 GHz channel bandwidth was initially set to 20/40 MHz, but the octoScope Pal test client kept disconnecting. Reliable connection was maintained when 20 MHz bandwidth was chosen for throughput vs. attenuation testing and 40 MHz bandwidth for peak throughput testing.
The router body was centered on the test chamber turntable with all antennas vertical as shown in the photo below. The 0° position for the router had the front facing the chamber antennas. You might think the 86U's antennas are too high for the chamber antennas to properly capture their signal.
ASUS RT-AC86U in test chamber
But I also tried the position shown below and found the standup position yielded better results, especially on 5 GHz. This is likely due to the vertical fixed position of the internal fourth 5 GHz patch antenna.
ASUS RT-AC86U in test chamber - face down
We'll start by comparing average throughput to get an initial feel for how the AC86 measures up. Average 2.4 GHz throughput of 64 Mbps downlink and 62 Mbps uplink slotted the AC86U in second and fourth place in the charts.
2.4 GHz average throughput comparison
5 GHz average throughput of 164 Mbps downlink and 263 Mbps up, landed the 86U in sixth and third positions.
5 GHz average throughput comparison
For the throughput vs. attenuation plots, I'm comparing the AC86 with NETGEAR's R7800 and R7000P and ASUS' GT-AC5300. For 2.4 GHz downlink throughput, only the R7000P breaks from the pack with much lower throughput under stronger signal (lower attenuation) conditions.
2.4 GHz Downlink Throughput vs. Attenuation
For 2.4 GHz uplink, the NETGEAR R7800 is the outlier, but in a good way.
2.4 GHz Uplink Throughput vs. Attenuation
5 GHz downlink is, as usual, more interesting, showing the greatest performance difference. Even though the AC86U runs four streams in 5 GHz, it acts more like the three-stream NETGEAR R7000P. The two four stream routers with all external antennas of the same design both perform better.
5 GHz Downlink Throughput vs. Attenuation
The 5 GHz uplink plot shows a tighter range of performance, as usual. Performance difference here is unlikely to be noticed in real world use.
5 GHz Uplink Throughput vs. Attenuation
Peak Wireless Throughput
For our peak wireless performance tests, the octoScope Pals are configured as 4x4 AC devices and left to negotiate their best connection, with 10 dB of attenuation applied on 2.4 GHz. The latter is necessary so the 2.4 GHz Pal isn't overloaded.
2.4 GHz Peak Wireless Throughput comparison - downlink
The AC68 does pretty well at 505 Mbps downlink and 339 Mbps uplink in these 2.4 GHz benchmarks. But since it's only three streams, it can't reach the same throughput as four-stream products, like NETGEAR's R7800 and ASUS' own RT/GTAC5300.
2.4 GHz Peak Wireless Throughput comparison - uplink
The 5 GHz peak benchmarks show the AC86U running closer to its four-stream brethren because it also is four stream.
5 GHz Peak Wireless Throughput comparison - downlink
911 Mbps downlink and 943 Mbps up mean you are essentially getting the equivalent of gigabit Ethernet performance. Keep in mind, this is with signal levels you're unlikely to encounter in real-world use.
5 GHz Peak Wireless Throughput comparison - uplink
I did not test MU-MIMO, because it generally doesn't provide significant performance advantages.
The ASUS RT-AC68U/NETGEAR R7000 "First Look" review has been in the top-five most read articles every week since it was published in October 2013 (!), an eternity in the Wi-Fi router biz. So the question is, is the AC86U (and NETGEAR R7000P) likely to now become perennial favorites?
Since it currently ranks #2 vs. the R7000P's #8 in the Router Ranker, the AC86 has more potential to become a favorite. The Most Popular Wireless Reviews - Trend page, which is updated weekly and shows the four-week trend of top 5 most read wireless router reviews, is where you can keep track. So far, it hasn't shown the R7000P to be particularly popular.
Instead, it's NETGEAR's R7800 four-stream Nighthawk X4S that seems to be getting steadier attention. But with the R7800 now ranking one step below the RT-AC86U's #2 spot and at around $30 higher, that might change soon.