Asus RT-AC66U 802.11ac router

Gordon Kelly

By Gordon Kelly



Our Score:


User Score:

Asus RT-AC66U - Performance

Asus RT-AC66U AC speedsSo how does this fiesty looking router perform? Impressively. In our test environment of 2m and 10m line of sight and 13m between two standing walls, the AC66U clocked 802.11ac transfer speeds of 39.1MBps (312.8Mbit), 31.2MBps (249.6Mbit) and 27.8MBps (22.2Mbit).

The first of these is the fastest we have seen from any router, besting the 36.7MBps (293.6Mbit) achieved by the Linksys EA6700. As distance increases the EA6700 regains the lead with 35.2MBps (281.6Mbit) and 28.8MBps (230.4Mbit), but the AC66U remains the second fastest ac router we have tested, edging ahead of the D-Link DIR-868L.

It was a similar story with 5GHz wireless performance with the AC66U falling between the D-Link and Linksys. 2m, 10m and 13m speeds managed 21.1Mbit (168.8Mbit), 19.8MBps (158.4Mbit) and 11MBps (88Mbit), which makes it second to the Linksys at 2m and 10m, but much faster at 13m and faster than the D-Link at 2m and 10m, but slower than its remarkable 14.1MBps (112.8Mbit) at 13m.

Asus RT-AC66U 2.4GHz speedsInterestingly - despite these excellent figures - the AC66U shines brightest at 2.4GHz 802.11n. It managed 11.6MBps (92.8Mbit), 10.6MBps (84.8Mbit) and 5.3MBps (42.4Mbit) at 2m, 10m and 13m respectively.

This makes it the fastest wireless ac router we've seen at 2.4GHz wireless n and much faster than the Linksys’ previous leading 13m benchmark of 3.3MBps (28Mbit).

In fact only the dedicated 802.11n D-Link DIR-845L can pip it at any distance with 5.5MBps (44Mbit) at 13m.

All of which means the AC66U won’t just bring you next generation speeds, it will significantly bolster speeds for your existing wireless n devices too.

As for performance via USB, like all other routers, it disappoints. The AC66U managed just 3.1MBps (24.8Mbit), which is a long way down on the USB 3.0 equipped Linksys EA6700 and D-Link DIR-868L [7.1MBps (56.8Mbit) and 4.9MBps (39.2Mbit) respectively] and it continues to show USB network sharing - while convenient - struggles badly compared to Gigabit Ethernet.

Why? While it differs from router to router, typically they lack enough memory to cache large amounts of USB data before firing it over their network. By contrast Ethernet is already part of the network and doesn't need caching.

Asus RT-AC66U 2

Should I buy the Asus RT-AC66U?

Based on wireless performance alone the AC66U is well deserving of your attention as it tussles successfully in all wireless n/ac tests with the two fastest routers we have seen to date. At £159.99 it also splits both routers in price with the Linksys EA6700 dearer at £169.99 and the D-Link DIR-868L a bit cheaper at £139.99.

If you can afford it we would still give the EA6700 the edge, despite its ropey 5GHz wireless n performance at range. This is because its Smart WiFi platform remains a real benefit, offering complete control of the router from any location with an internet connection. Mydlink is far more limited in this way, but you save money and D-Link has a Cloud platform to develop while Asus is keeping schtum on any fully fledged Cloud platform plans for now.

We can’t see any purchasers being disappointed in the AC66U, but given performance levels are beginning to even out it is the extras which are starting to make the difference.

For more alternatives, read our top 10 best routers round-up.


The Asus RT-AC66U is a superb router, but it's not quite our favourite. It's very, very fast, which is great news if you only care about performance, but rivals have a few more features we'd like Asus to add.

Overall Score


Scores In Detail

  • Build Quality 8
  • Design 7
  • Features 8
  • Performance 9
  • Usability 8
  • Value 7


July 31, 2013, 8:46 pm

It's also worth noting (in these days of greater privacy awareness) that this model has a VPN server built in.

I upgraded a while back to the RT-N66U (the 'n' version of this router) and it's an absolutely fantastic bit of kit. The VPN server was a big draw for me as it offers me the ability to surf securely via my own ISP when on public wifi.
Asus also do an Android & iOS app that enables you to remotely access computer shares within your network, perform Wake on Lan operations remotely, etc.
Added to that N66U is the only router I've come across that will update firmware without kicking you off the network - surely a sign of the attention to detail.

Nate Ebner

July 31, 2013, 11:06 pm

Sounds good. Thanks for adding your comments.

Nate Ebner

July 31, 2013, 11:08 pm

Thanks Gordon. This was a well done informative review, not that I'd expect anything less.
Given if we get it, it will go in the loft (bungalow), flashing lights and looks are not a very big deal.

Gordon Kelly

August 1, 2013, 8:53 pm

Thanks! To be honest, while there are a lot of flashing lights they are quite small and not overly bright so they're not too much of an annoyance. Enjoy the new bungalow!

Ayman Sartawi

August 2, 2013, 11:05 pm


if you had to choose between the AC66U and the EA6700 ! what would you choose ?

Gordon Kelly

August 3, 2013, 12:49 pm

One got an 8 the other got a 9, so it is the EA6700 for me, but both are excellent routers and you will not regret buying either.

Ayman Sartawi

August 3, 2013, 2:41 pm

the EA6500 also got a 9 !! would you go for that ?! i'm using the EA6500 now and it's the worst Cisco router i've ever used, and i've used a lot of Linksys, E3000 is a very stable one, Cisco routers have no DD-WRT support anymore which is also bad.

Gordon Kelly

August 3, 2013, 2:55 pm

All reviews are scored for their time. The EA6700 is a step up from the EA6500 in terms of performance, but the EA6500 is still a fantastic router. Not sure what problems you're having, I used the EA6500 as my own router for 6 months before switching to the EA6700 and never encountered a problem. It was rock solid and blazing fast.

To be honest if you're buying a Linksys router (Cisco sold Linksys to Belkin recently) in order to swap the Cloud-based Smart WiFi for DD-WRT that's a backwards step to me. Smart WiFi is an infinitely superior platform in my opinion - the best and most intuitive on any router currently - and I can see why Linksys wouldn't want it messed with.

But if you want DD-WRT I'd go for the Asus. It is slightly cheaper and there's very little to choose between it and the EA6700 in terms of performance.


August 26, 2013, 7:45 pm


I've been researching new routers the past couple of days and am stuck between the Asus RT-AC66U, the D-Link DIR-868L, and the Linksys EA6700. I'd like a reliable fast router but the thought of being able to access content on a USB connected hd is also pretty enticing. All 3 more or less do that as well. So it comes down to it, which one would you recommend? I've read all 3 reviews, and I still can't make up my mind.



September 16, 2013, 10:16 am

Reasonably fast - however, it cannot accept automatic website backups via ftp to be copied to my local NAS - Asus just tell me it can't do that. Manual ftp is fine - but a router that blocks automatic connections for website backups is pretty useless in my opinion.

Sent back for refund.


October 3, 2013, 6:18 pm

What? FTP is FTP. If it's manual or automated, it's the same protocol.

Arjen de Jong

October 20, 2013, 1:47 am

I have a lan 2tb western digital mybookworld and with aicloud see it but asks for a login and password but nothing I put in works... I'm I missing something on the Asus rt-ac66u settings?

Linda Bissonnette

December 12, 2013, 12:56 am

Garbage the router is HOT to the touch can't even handle what I've got connected in the house without being hot. I e-mail ASUS customer support only to get an e-mail back with a phone number long distance on a warrantied product. The router sucks as well as the customer service. Last ASUS product garantee


March 14, 2016, 8:18 pm

Asus AC1750 is compatible with over 30 units

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