Four Stream Performance
TRENDnet supplied two TEW-827DRUs so maximum 4x4 throughput could be tested. The two routers were set up in open air, six feet apart, one as a normal router and the other in wireless bridge mode. The in-house 5 GHz network was idle and only beaconing (no traffic). Channel was set to 153, bandwidth mode was in its default 80 MHz mode and everything else was set to defaults, including MU-MIMO enabled. Given the 4x4-to-4x4 nature of the link, MU-MIMO doesn't come into play.
An interesting side note is the 827DRU's bridge settings include both a MU-MIMO enable and the ability to set the number of spatial streams. So if you're looking for a MU-MIMO client device to experiment with, the 827DRU is one option, albeit an expensive one. I left the bridge MU-MIMO setting in its default disable setting.
TRENDnet TEW-827DRU Bridge mode MU-MIMO settings
Only one computer was connected via Gigabit Ethernet to each 827DRU. Baseline tests using Ethernet between the two computers show the Ethernet link capable of a bit over 940 Mbps in both directions with each direction run separately. So the hardwired part of the link shouldn't be a limiting factor. The bridge status screen includes link rate, which showed the maximum 1733 Mbps achievable by a 4x4 connection. This is the first time we've seen this link rate when testing 4x4 maximum wireless throughput.
The simultaneous up and downlink test yielded 960 Mbps total throughput, as the IxChariot plot shows. Note the significant difference in up and downlink throughput, with downlink almost 3X uplink.
TRENDnet TEW-827DRU four stream throughput - simultaneous up/downlink
Separate up and downlink tests that yielded 766 and 711 Mbps vs. 739 Mbps downlink and 652 Mbps uplink for the Archer C2600. The plot shows pretty steady throughput in each direction.
TRENDnet TEW-827DRU four stream throughput - up and downlink
A second pair of clients was plugged into the router and bridge to see if a second connection pair would yield higher throughput and to ensure that the single Gigabit Ethernet connection was not limiting results.
The plot shows a total 1061 Mbps throughput, somewhat more than the single-pair simultaneous uplink / downlink test above. Pair 3 (downlink) had both the fastest throughput at 475 Mbps, but also the highest variance. Pair 7 seemed starved for throughput at 81.8 Mbps. In total, downlink (pairs 3 & 5) dominated with a total throughput of 694 Mbps vs uplink (pairs 6 & 7) with 373 Mbps.
TRENDnet TEW-827DRU four stream throughput - simultaneous up/downlink, four computers
Testing and analysis by Tim Higgins
I've been relying on companies to send three MU-MIMO devices along with their MU-MIMO routers so we can test this feature. But now that I've vetted the Ixia VeriWave (aka IxVeriWave) system, I'll be using it for MU-MIMO testing going forward and adding MU-MIMO benchmarks to the Router Charts.
The hardware and test method is essentially the same used in Is MU-MIMO Ready For Prime Time?. The test looks for how much total throughput increases using MU-MIMO and how long the higher throughput lasts as more MU clients are added.
What you'd like to see is higher MU than SU throughput for as many STAs as possible. In the interest of having a reasonable test time (this test takes over an hour to run), we test only out to 16 STAs, because it's our experience that the MU and SU lines usually converge before then.
The 827DRU's four antenna connections were cabled to the IxVeriWave Wi-Fi Blade. Each connection had a 50 dB fixed attenuator to reduce signals to the required ~30 dBm input level. The photo below shows the 827DRU connected to the IxVeriWave chassis, ready for testing.
TRENDnet TEW-827DRU ready for MU-MIMO test
The custom test script VeriWave developed starts with a single MU 1x1 STA, configured to connect at MCS 9 index rate, 80 MHz bandwidth and short guard interval to achieve the maximum 433 Mbps link rate. MIMO channel models (A-F) were not used; bypass mode was set.
The test connects the STA, then runs a TCP Goodput (throughput) test, with MSS, Window and Frame size set so the Gigabit link is fully loaded. Each test runs for 30 seconds and throughput is recorded at the end of the test. We used a single TCP/IP session (connection) for each test.
The test then adds another MU STA, verifies connection, repeats the 30 second test and records throughput for each STA, up to a maximum of 16 STAs. The entire test sequence is then repeated with the STA mode set to SU (Single User), to see how total throughput behaves with non MU devices. We run the whole test twice and publish the average results.
The composite plot below shows SU throughput gradually declining from a high of 337 Mbps to 289 Mbps, a loss of about 15%. MU throughput drops below SU for two STAs (it shouldn't), then peaks at 418 Mbps for three clients; a 25% best case gain. Higher throughput continues out to 7 STAs, then either matches SU throughput or drops below it.
TRENDnet TEW-827DRU MU-MIMO performance
For comparison, let's look at how the Linksys EA8500 did on the same test. The Linksys properly had higher throughput with two STAs and peak MU throughput of 730 Mbps with three STAs; a little over 2X the 342 Mbps best-case SU throughput. After a brief dip below the SU line with four clients, MU throughput stays above SU out to 11 STAs. SU throughput declined only 9% from 342 Mbps with one STA to 311 Mbps with 16 STAs.
Linksys EA8500 MU-MIMO performance
The good news is the TEW-827DRU's MU-MIMO operation looks fairly stable. The bad is that total throughput gain is nothing to write home about and SU throughput declines more than it should as more STAs are added.
The Router Ranker shows that the TP-LINK Archer C2600 still claims the #1 ranking for AC2600 class routers. The TRENDnet TEW-827DRU pushed the Amped Wireless RTA2600 down a notch to claim third place. Keep in mind our current ranking method does not take MU-MIMO performance into account.
AC2600 Class router Total Router Ranking
The composite ranker performance summary chart below compares the top three performing routers. While the TRENDnet TEW-827DRU was ranked #3 overall, for wireless performance it had a #2 ranking in five out of six wireless performance categories.
Router Ranker Performance Summary
We're usually not that impressed with TRENDnet routers' wireless performance; you can usually find their products at or near the bottom of the Router Ranker. Although that's also the case for the TEW-827DRU—it ranks 3 out of 4 in the AC2600 class—the good news is it outperformed the Amped Wireless RTA2600, a product Amped is already replacing with a new version. The 827DRU's wireless performance is actually more competitive in its class than its other routers.
But the 827DRU's MU-MIMO performance needs some work. The composite plot below taken from Is MU-MIMO Ready For Prime Time? shows three other 4x4 MU-MIMO enabled routers have much higher peak throughput gain. But at least the 827DRU's MU-MIMO showing isn't as bad as the Amped RTA2600. Its MU-MIMO doesn't really work.
All products - MU total throughput vs. STAs
Before you rush to buy, remember you need at least two MU-MIMO devices to reap the improved total wireless bandwidth yield of a MU-MIMO router and those devices are still essentially MIA here in the U.S. But if you just gotta have an AC2600 class MU-MIMO router, the TP-LINK Archer C2600 looks like your best buy for now. It still has the best router ranking, and happily is also the cheapest AC2600 class router right now.