I made my case for not buying AC1900 routers months ago in AC1900: Innovation or 3D Wi-Fi? But according to the router makers I spoke with at CES a few weeks ago, they are selling like gangbusters. This is primarily because early adopters who have been driving most of the AC router buying so far aren't concerned about price; they just want the biggest, baddest router they can get. Manufacturers, of course, are loving this, because they can sell fewer routers and make as much, if not more money.
SmallNetBuilder has always been about making fact-based decisions. So in the interest of getting more facts to test my not-so-rosy opinion of AC1900 routers, I did some additional testing of 2.4 GHz performance for the three AC1900 routers sucking money out of wallets today: ASUS' RT-AC68U; NETGEAR's R7000 Nighthawk; and Linksys' EA6900. The ASUS and NETGEAR were originally reviewed here and the Linksys here.
AC1900 vs. AC1750 Adapter Test
My primary objection to AC1900 routers is that most clients can't achieve the 2.4 GHz 600 Mbps link rates that are the main reason for this class' existence. That's why my testing has continued to use ASUS' PCE-AC66 AC1750 class client, vs. its AC1900 class replacement, the PCE-AC68.
I also had not been able to switch to using the AC68 even if I wanted to, because ASUS had not released a driver that enabled 600 Mbps link rates. That latter obstacle changed in mid-December, when ASUS released the 188.8.131.52 version of its driver/utility for the PCE-AC68. So I went back and retested the three AC1900 routers' 2.4 GHz performance using the PCE-AC68 and the new driver.
I first upgraded each router to its latest released firmware, i.e.:
- ASUS RT-AC68U: 184.108.40.206.374_371
- Linksys EA6900: 220.127.116.11465
- NETGEAR R7000: 18.104.22.168
(Yes, I know ASUS released 22.214.171.124.374.583 on 1/14/2014. But I already had done a lot of testing with 126.96.36.199.374_371, so wasn't going to change.)
I then ran 2.4 GHz up and downlink profiles with the rear of the router facing the test chamber antennas 8" away. Before starting the test run in each case, I checked that the PCE-AC68 did indeed link at 600 Mbps (or at least at rates above the 450 Mbps maximum link rate for non 256-QAM operation). The Linksys EA6900 was the only router of the three that showed a 450 Mbps link rate.
After I ran the tests with the AC68 adapter, something told me that I should run the tests again, but with the PCE-AC66 adapter. Since router firmware had been updated, I didn't want to just reuse the old test data. I then pulled each set of results into comparative plots, which revealed surprising results. Let's start with the ASUS RT-AC68U.
ASUS RT-AC68U 2.4 GHz downlink - PCE-AC66 vs. PCE AC68 adapters
Theoretically, a jump from 450 to 600 Mbps link rate should provide a 33% throughput gain. If there is such a gain in these plots, I sure can't see it.
ASUS RT-AC68U 2.4 GHz uplink - PCE-AC66 vs. PCE AC68 adapters
The Linksys EA6900's results were quite different, but not in a good way.
Linksys EA6900 2.4 GHz downlink - PCE-AC66 vs. PCE AC68 adapters
Since the AC68 adapter reported only a 450 Mbps link rate, the results shouldn't be any worse than the AC66's. But they clearly are much worse.
Linksys EA6900 2.4 GHz uplink - PCE-AC66 vs. PCE AC68 adapters
The NETGEAR R7000 fared a bit better than the Linksys. But it still had overall lower throughput with the AC68 adapter, even though it linked at 600 Mbps.
NETGEAR R7000 2.4 GHz downlink - PCE-AC66 vs. PCE AC68 adapters
I say a bit better, because the curves tended to come together at lower signal levels, at least for downlink.
NETGEAR R7000 2.4 GHz uplink - PCE-AC66 vs. PCE AC68 adapters
Call me suspicious, but I think it's odd that the ASUS did the best out of the three tests conducted. But, even then, it managed only to not lose throughput using a 600 Mbps link rate adapter. So if there were any benefit to using a "matched" AC1900 router and client from ASUS, it appears to be only in maintaining the same performance as you get using ASUS' PCE-AC66 adapter.