Wireless Performance - 5 GHz Three Stream N
For the three-stream N 5 GHz test runs, I set the WZR-D1800H to Channel 36 and used its 11n/a Normal Mode (20MHz) mode for the 20 MHz mode tests and its 11n/a 450 Mbps Mode (40MHz) for the 40 MHz tests. I also could have used the 11ac/n/a 1300 Mbps Mode (80 MHz) mode for the 40 MHz mode tests with my three-stream N client. Since the Intel 6300 client doesn't know how to speak draft 11ac, the D1800H looks like a standard "N900" router to it.
I confirmed this by setting the router to the 80 MHz mode and running a quick IxChariot test, while monitoring spectrum with the Wi-Spy dBx. The Wi-Spy showed only Channels 36 and 40 in use, i.e. 40 MHz of bandwidth and Win 7's Wireless Network Connection Status showed a 450 Mbps link rate. Like three-stream N before it, a draft 11ac router offers no performance advantage to non 11ac clients.
The Performance Table for Three-stream 5 GHz shows exceptionally strong throughput for the ASUS "Dark Knight" running uplink in both 20 and 40 MHz modes.
The D1800H's strongest showing is in downlink, 40 MHz bandwidth mode. But it wasn't strong enough to beat the NETGEAR WNDR4500.
The IxChariot plot in Figure 6 again shows high throughput variation, which you'll also see in most of the other benchmark plots.
Figure 6: Buffalo WZR-D1800H IxChariot plot summary - 5 GHz, 20 MHz mode, downlink, 3 stream
- 5 GHz / 20 MHz uplink
- 5 GHz / 20 MHz up and downlink
- 5 GHz / 40 MHz downlink
- 5 GHz / 40 MHz uplink
- 5 GHz / 40 MHz up and downlink
Wireless Performance - 5 GHz - Draft 11ac
We finally reach the draft 11ac tests. For these, I paired the D1800H with a Buffalo WLI-H4-D1300 draft 11ac bridge and set the router to its 11ac/n/a 1300 Mbps Mode (80 MHz) on Channel 36. Since there are no other draft 11ac products to compare, the Performance Table in Figure 7 is pretty compact.
Figure 7: Buffalo WZR-D1800H Performance Table - 5 GHz, 80 MHz (draft 11ac)
The tests show that the throughput of the D1800H / D1300 Buffalo pair hold up pretty well over range. While the data doesn't really show it, because I don't have other intermediate test points, 5 GHz draft 11ac seems similar to 802.11n in that throughput falls off pretty drastically once signal levels drop enough.
To see whether the throughput vs. range curves varied among modes, I created the plots in Figures 8 and 9. The 80 MHz draft 11ac mode curve seems the most linear and runs roughly parallel to the 40 MHz mode curve.
Figure 8: Buffalo WZR-D18008 throughupt vs. location by bandwidth mode - downlink
Figure 9 shows uplink results, with 40 MHz mode taking a big jog downward in 40 MHz mode.
Figure 9: Buffalo WZR-D18008 throughupt vs. location by bandwidth mode - uplink
How stable is the 80 MHz mode throughput? The IxChariot plot summary in Figure 10 shows that it's not bad...if you don't mind occasional very large throughput dropouts. It's interesting that the dropouts didn't appear in the lowest signal level test in Location D.
Figure 10: Buffalo WZR-D18008 IxChariot plot summary - 5 GHz, 80 MHz mode, downlink
Speaking of link rate switching, I could see a good deal of it by looking at the D1300 bridge's Diagnostic page and Windows' standard Wireless Connection properties. In 802.11n, three-stream 40 MHz mode, I very occasionally saw a full 450 Mbps link rate during the Location A tests. And the rates in all test locations and modes seemed to move around a good deal during testing. Since it is early days for draft 11ac—I expect algorithm tuning is still underway and will be for awhile.
Here are links to the other plots for your reference.