Client Interoperability

The RT-AC87 represents the debut of Quantenna's QSR1000 chipset in a consumer router. So I gathered the same assortment of devices used to test the Linksys WRT1900AC's interoperability, gave each a one minute test and summarized the results in Table 1. For this test, the AC87 and devices were in the same room within 6 feet of each other. Channel 6 and 20 MHz mode were used for 2.4 GHz; channel 153 and 80 MHz mode were used for 5 GHz.

You'll note the Android tests all failed to run uplink. I chalk this up to a problem with the recently updated IxChariot Android app, not something wrong with the router.

The good news is that everything I tried was able to connect to the AC87 just fine. The best overall performer of the bunch was the Linksys AE6000 1x1 AC580 adapter based on MediaTek's MT7610U. Its uplink and downlink throughput was smooth and evenly matched on both bands. You can get a better feel for each clients performance by clicking through the IxChariot plots.

Four Stream Performance

The real reason you're thinking of buying this thing is a shot at its maximum 5 GHz 1733 Mbps link rate, right? Unfortunately, you may be sorely disappointed. To give the products their best shot, I set them up in open air, six feet apart. I didn't shut off my in house 5 GHz network for the test. But it was idle and only beaconing (no traffic).

To not limit potential throughput by using a single Gigabit Ethernet port (after all, we're talking about a 1733 Mbps maximum link rate), I used two pair of Gigabit Ethernet connected computers to run two IxChariot streams simultaneously. Channel was set to 153, bandwidth mode was in its default 80 MHz mode and everything else was set to defaults, which included both forms of beamforming enabled (not that it should make a difference at such a short distance).

The results were disappointing. During multiple attempts, I saw link rates above 1300 Mbps (indicating 4 stream operation) only once on an uplink test. In most cases, link rates hovered around 950 Mbps. The downlink plot below shows 720 Mbps of total downlink throughput from the two streams—about what I got in the stress test using two NETGEAR 3x3 R7000 bridges.

ASUS RT-AC87U four stream downlink throughput

Uplink was about the same at 702 Mbps.

ASUS RT-AC87U four stream uplink throughput

The 3.0.0.4.376_2061 firmware used for this test, and all others in this article, is supposed to contain the latest Quantenna driver. But it doesn't appear to have helped. I ran the same test with 3.0.0.4.376_2044 firmware a few weeks ago, with similar results.

Closing Thoughts

As I said in the closing to Part 1, the RT-AC87U/R is an unfinished product, rushed to market when it should still be back in the lab being thoroughly debugged. If you want to put your faith in ASUS and Quantenna's ability to deliver on its "wave 2" 802.11ac features (1733 Mbps link rate and MU-MIMO), go ahead and give ASUS your money now. After all, being the first on your block to have a new toy is worth it, right?

Smart buyers, however, will cool their jets and either buy something else or wait another few months until MU-MIMO support is turned on and ASUS ships its matching EA-87 client. They better have 5 GHz performance sorted out by then. Because the RT-AC87 won't be the only four-stream AC router in town at that point.