More Connections Per Client
Qualcomm says MU-MIMO throughput improvement is even better with multiple connections per client, as might happen when your web browser launches a lot of simultaneous connections in its effort to quickly render a page. The three test scenarios were rerun with three connections per client.
The results show more modest overall throughput gains. But all clients and connections showed higher throughput with MU-MIMO enabled. Some gains were as low at 8%. The "ideal" triangle configuration yielded only a modest 73% total throughput gain.
MU-MIMO Throughput change - Triangle - 3 connections / client
The "torture test" All Front configuration a total throughput improvement of 99%, but each client had better performance with MU-MIMO enabled that with it disabled. The range on the % change, however, ranged from a low of 10% to a high of 272%.
MU-MIMO Throughput change - All Front - 3 connections / client
The three room test with three clients turned in some fairly unexpected results. The only location that showed gains with MU-MIMO enabled was the "In Room" location where the signal strength was the strongest. In each of the other two locations, all three of the clients actually had poorer throughput with MU-MIMO enabled than with it disabled.
In total, the MU-MIMO results eked out a negligible 7% throughput change only because there were significant gains from the three in-room clients. This is particularly disturbing, since the three room test with weaker signal strengths is probably closer to what you'd see in real world use. Since we know that the technology works from at least other manufacturer's implementation, we're left to question what's happening in NETGEAR's implementation.
NETGEAR R7500v2 MU-MIMO Throughput change - 3 room - 3 connections / client
For comparison, here's the same 3 room - 3 connections / client chart for the TP-LINK Archer C2600. Notice how that for each client in each location performance improves with MU-MIMO enabled, and the total throughput change is 147%.
TP-LINK Archer C2600 MU-MIMO Throughput change - 3 room - 3 connections / client
NETGEAR isn't alone in terms of problems on the three room tests. The composite image below shows the 3 room chart for the Linksys EA8500 (left) and the Amped Wireless RTA2600. Note that for the Linksys EA8500, the 3 room test was only performed with a single client as it was the first MU-MIMO product reviewed. Our MU-MIMO tests have continued to evolve since then. The Amped Wireless RTA2600 chart (right) show results for 3 room - 3 connections / client tests that corresponds to the two charts shown above.
The results for the Linksys EA8500 were very similar to what we saw for the NETGEAR R7500v2. In both cases, the only location showing throughput gain with MU-MIMO enabled was the "In Room" location. The Linksys posted a total throughput change of 11%, compared to the NETGEAR's 7%. The Amped Wireless RTA2600 fared even worse. For the In Room location, two of the three clients had better performance with MU-MIMO disabled, and all three clients were better off with MU-MIMO disabled for the hall location. In terms of total throughput change, the Amped Wireless RTA2600 would have been better off without MU-MIMO, as it posted a -10% throughput change.
Linksys EA8500 (l) and Amped RTA2600 MU-MIMO Throughput change - 3 room
An Alternate View
We also tested the R7500v2 using a VeriWave test system as part of our Is MU-MIMO Ready For Prime Time article. The VeriWave system allowed us to see how MU-MIMO scales, testing total throughput for up to 16 1x1 MU-MIMO ideal clients and comparing it to the same number of SU clients. The R7500v2 was tested along with the Amped Wireless RTA2600, Linksys EA8500 and TP-LINK Archer C2600. The results were very revealing, with the R7500v2 being one of the better routers at handling lots of MU-MIMO clients.
As noted in the introduction, the NETGEAR Nighthawk X4 R7500v2 is a bit of an oddball, being the only AC2350 class router with working MU-MIMO. It's likely to remain that way since there is no sign of any Quantenna-based 4x4 router getting its MU-MIMO wings. And it's unlikely any other manufacturer will introduce a QCA based router that isn't AC2600 class.
The most logical explanation is NETGEAR has chosen Broadcom as its mainstream 4x4 technology provider, and didn't want the job of explaining the difference between three MU-MIMO classes, i.e. AC2350, AC2600 and AC3100. Since NETGEAR has already introduced its Broadcom-based 4x4 "tri-band" R8500 Nighthawk X8 [reviewed], it's likely they'll follow up with a CES 2016 introduction of an AC3100 sibling in a few weeks. In fact, the R7800 Nighthawk X4S posted in the FCC ID database may be that product.
Here's how the NETGEAR R7500v2 stacks up against other AC2350 routers. Note that MU-MIMO is not a component of our Router Ranker ratings. The chart below shows that the NETGEAR R7500v2 is ranked #2 behind the ASUS RT-AC87U.
AC2350 Total Router Rank
Here's the performance summary comparing both NETGEAR R7500 versions with the top-ranked ASUS RT-AC87U. The NETGEAR R7500v2 did outperform the top-ranked ASUS RT-AC87U for both 5 GHz average throughput as well as 5 GHz maximum throughput. It also tied the other two routers for maximum simultaneous connections since each supported more than 30,000.
Performance Summary Comparison
However, we can't really recommend buying any 4x4 router with a Quantenna 5 GHz radio. As noted at the start of this review, manfacturers have moved on to newer 4x4 products and so should you.
So assuming you've convinced yourself that a 4x4 router is the way to go, the real question is AC2600 vs. AC3100 (QCA or Broadcom). If you need working MU-MIMO today, your only choice is AC2600 because QCA-based routers have shipped with MU-MIMO from day one. For AC3100, you're buying a MU-MIMO "capable" router, with working MU-MIMO coming somewhere between the end of this year and early next, according to disclaimers posted for AC3100 and AC5300 products.
If you don't care about MU-MIMO and just want the best chance for improving Wi-Fi coverage, it's unlikely either flavor of 4x4 router is going to help in 5 GHz. Our recent comparison of many of the latest and greatest AC routers found decent throughput gains in a medium-low signal location in 2.4 GHz, but throughput loss in 5 GHz in many cases, compared to a top-performing AC1900 class router.
The bottom line is the R7500v2 is a decent 4x4 router and may even be one of the better ones at handling a lot of MU-MIMO devices (if you have them). But there is little to recommend it over the AC1900 R7000 and the downside of the potential hassle of having to buy and return it multiple times to get a v2 if you buy online.