The R6250 is Wi-Fi Certified. It defaulted to Auto Wireless mode and Auto channel selection on both Control and Extension channels and 20/40 MHz channel bandwidth on both bands on first power up. The 2.4 and 5 GHz radios are set to different SSIDs by default.
Attempting to connect a client to the router before running the manadatory setup wizard caused my Win 7 client to initiate a WPS PIN session on the 2.4 GHz radio. After entering the PIN printed in tiny type on a sticker on the back of the router, the session completed quickly in a WPA2/AES secured connection with the same SSID and passphrase applied to both radios.
The 5 GHz radio, in contrast, is not protected by default, so I was able to connect with no security there. (WPS can be enabled for only one radio at a time and 2.4 GHz by default.) But all I could do was walk through the setup wizard; there was no internet connection allowed. Even after completing the WPS PIN session, the wizard still presented wireless settings for me to change.
I ran 40 MHz Coexistence and Fat channel intolerant tests to make sure the N65U behaved when encountering interfering 2.4 GHz networks. The N65U immediately fell back to 20 MHz mode link rates when the Fat Channel Intolerant bit was set on the client. But when the Fat Channel Intolerant bit was set back to disable, the router stayed at 20 MHz mode link rates for the few minutes that I monitored it. After rebooting the router to re-establish a 40 MHz connection, I tried the 40 MHz coexistence test that passed with flying colors.
All tests were run using our new wireless test process and 220.127.116.11.342 version firmware loaded. The router was first reset to factory defaults and Channel 6 was set for 2.4 GHz and Channel 153 for 5 GHz. 20 MHz B/W mode was set for 2.4 GHz and 40 MHz B/W mode was set for 5 GHz. The test client was connected using WPA2/AES encryption.
The router was positioned 8" from the chamber antennas in all test positions. The 0° position had the router front facing the chamber antennas.
The Benchmark Summary below from the new Consolidated benchmark process shows the average of throughput measurements made in all test locations. The 2.4 GHz values in the summary correspond to 2.4 GHz values (20 MHz B/W) and the 5 GHz values correspond to the 40 MHz B/W - 3 stream values measured with the previous test methodology.
The N65U is the first N750 router tested with our new process, which tends to yield higher wireless throughput than our previous test method. Despite this, the N65U's 2.4 GHz performance wasn't particularly outstanding. Its highest downlink throughput of 85 Mbps did put it in the #1 spot for that benchmark. But the next best Linksys EA3500 measured 78 Mbps. Maximum 2.4 GHz uplink throughput had more of a separation between the two, with the N65U hitting 95 Mbps and the Linksys staying down at 76 Mbps. The N65U's simultaneous up/downlink test turned in 102 Mbps of total throughput. The second-best EA3500 yielded 94 Mbps.
The EA3500 continued to nip at the N65U's heels for the 5 GHz benchmarks. Maximum downlink throughput for the N65U and EA3500 respectively was 136 and 105 Mbps, while uplink came in at 151 and 121 Mbps. The biggest performance difference was found in the simultaneous 5 GHz up/down tests. Here, the N65U produced a total throughput of 165 Mbps, while the next-best Linksys EA3500 mustered only 93 Mbps.
Because I have throughput vs. attenuation data for only the N65U, the plots aren't that helpful for competitive comparison. The important thing to note in the 2.4 GHz downlink plot below is the 1 Mbps value at 60 dB attenuation, which is used in determining the downlink range ranking. A value this low certainly contributed to the N65U's low ranking among its N750 class competitors.
2.4 GHz Performance Table
Here are the other profile plots if you'd like to take a look:
So I'll instead turn to older tools. The Performance Table below compares the N65U with three other relatively recent top-ranked N750 products, the Linksys EA3500, Belkin N750 DB and EnGenius ESR750H. As noted in the initial performance summary above, the N65U distances itself from the competition more widely running uplink than downlink. That is, except for in Location F, which is used for Range Ranking. The N65U's performance there is rather anemic, with only 1 Mbps for downlink and 0 for uplink (meaning the test did not run).
2.4 GHz Performance Table
The 5 GHz table shows very high Location A (0 dB) throughput both up and downlink. But in Location D, which is used for 5 GHz range ranking, the N65U manages to beat only the EnGenius ESR750H.
5 GHz Performance Table
We've come to expect high performance from ASUS routers. But it's a mixed story for the RT-N65U, coming in tied at the #3 rank with the Linksys EA3500 among tested N750 class routers. The Ranker performance summary below shows that its poor simultaneous routing throughput produced one ranking hit with a #5 routing throughput rank. The second blow was delivered by the #4 wireless range ranking, which was low for both 2.4 and 5 GHz benchmarks.
ASUS RT-N65U Router Ranking Performance Summary
In contrast, let's look at the RT-N56U ranking, which comes in at #1 among N600 class routers. In contrast with the N65U's 574 Mbps of simultaneous routing throughput, the N56U came in at 1269 Mbps, second only to the wired-only Ubiquiti EdgeMAX EdgeRouter Lite. The other key contributor to the N56U's higher rank is its #2 range rank, which helps to offset its #3 wireless throughput rank.
ASUS RT-N56U Router Ranking Performance Summary
The main thing the N65U had going for it over the N56U was its USB 3.0 ports. But since they can severely affect 2.4 GHz wireless performance, they turn out to be more of a liability. In the end, the bread slices of the RT-N56U / RT-N65U / RT-N66U sandwich are better than the meat in the middle.