The Joys of 802.11ac WiFi
by Jarred Walton on July 8, 2013 8:15 PM ESTClosing Thoughts (for Now)
It’s really up to the notebook manufacturers to make sure that their WiFi implementations are up to snuff, and that means doing more than a quick test for connectivity in ideal test conditions. The QA and engineering departments at the very least ought to be testing at 5, 25, 50, and 100 feet, using standard Windows operations (i.e. not just IxChariot or iPerf). If there are issues, they should be ironed out before customers (and reviewers) get the product. With that said, a good foundation for wireless networking can go a long way toward improving bandwidth and stability of your connection.
Intel’s adapters aren’t always the best, but they’re rarely the worst, provided you get one of the non-budget offerings (i.e. avoid the 1000 and 2000 series parts). Realtek unfortunately comes in near the bottom of my ranking list in many cases, but most notebooks with Realtek WiFi are already cutting corners—they’re the 1x1:1 2.4GHz only solutions that are so common. The fact is, whether you're using an adapter from Qualcomm/Atheros, Broadcom, Marvell, Realtek, or Ralink, you can have a good adapter in some cases or a downright awful one in others. Broadly speaking, most solutions with two streams end up being better than any of the single stream solutions.
Of course, it's not just about spatial streams. Oddly enough, for a company that has been on the forefront of wireless technologies, as Anand detailed in our MacBook Air 2013 review OS X is not scaling TCP window size beyond 64KB and thus fails to get optimal performance out of 802.11ac. (I assume an OS/driver patch will address this at some point, but that hasn't happened yet AFAIK.) OS and driver issues can definitely put a clamp on WiFi performance, which again is why the notebook makers need to exercise due diligence and test in real-world scenarios to ensure their hardware is working properly.
As I said earlier, one of the best things about 802.11ac wireless is that it raises the bar for wireless adapters. No one can get away with selling you an 11ac adapter without including at the bare minimum a dual-band chipset with support for 5GHz and 2.4GHz networks. If you live in a packed subdivision or apartment complex, 5GHz networking is almost required these days. Ideally, though, I want more than just the bare minimum; I want two 80MHz streams on my 802.11ac connections, and three would be even better. Intel’s 7260 provides two streams, and so do most of the current crop of 802.11ac routers. Hopefully, we won’t see as many solutions going for the bottom of the barrel single stream implementations; they’re not worse than 802.11n, but they’re not much better than two stream 5GHz 802.11n either.
Consider this a warning shot across the bow of the notebook manufacturers: we’re going to be paying more attention to your wireless implementations going forward. I can understand why a $500 or less budget laptop needs to cut every corner possible to hit that price point, but when we’re looking at $1000+ laptops we don’t want to see such blemishes. It may not always be as painful as using a bad LCD on an otherwise excellent laptop, but a bad WiFi implementation that loses connectivity if you’re more than 40 feet from the router in can be even worse in some cases.
We’ll be doing some full reviews of 802.11ac routers in the near future, including the Western Digital AC1300 and Linksys AC1200. The full reviews will better characterize performance as well as other features. Until then, at least right now it looks like most 802.11ac routers are using two streams (867Mbps maximum theoretical throughput), which is at least a nice upgrade over the 300Mbps so many 802.11n routers offer. Meanwhile, Apple's latest AirPort Extreme and Time Capsule go whole hog and give us three streams and up to 1300Mbps. Now if I could just get (Windows) laptops with three 802.11ac streams, I might actually be willing to give up my Gigabit Ethernet and wires!
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Modus24 - Tuesday, July 9, 2013 - link
I have an RT-AC66U and I get a ~250 Mbps file transfer rate from 20 feet away using 5 GHz 802.11n. I get ~500 Mbps between floors using an 802.11ac bridge.DroidTomTom - Tuesday, July 9, 2013 - link
What are you using for the client adapter? Those are great speeds. I can not get my IntelCentrino Advanced-N 6235 client to connect faster than 133Mbps to my Linksys EA4500 N900 host router. Let alone attain decent sustained speeds. Even living in the dead of nowhere.Streetwind - Tuesday, July 9, 2013 - link
Honestly these test numbers are apalling. In the home theater test, even the 5 GHz ac adapters failed to match 100 Mbps wired ethernet except for the best of the best implementations - and we've been on gigabit ethernet for how many years now? I'm intentionally not looking at the 5 feet results, because those are often completely unrealistic when you try to provide wireless coverage in your entire house. In fact, I even think somewhere around 30-40 feet would be more representative than 20, considering Jarred is stating here that 50 feet isn't even making it to his driveway.Another thing I've always wondered about and never saw tested anywhere is the stability of the connection quality. Wireless transfer rates can often fluctuate wildly even when both endpoints are completely stationary, and even moreso when one of them moves. A mean time taken to transfer a file doesn't tell nearly the entire story about connection quality and latency. Those are a big deal for things like VoIP, content streaming and online gaming, for example. Jarred, I don't suppose you could screenshot some of those pretty graphs that Windows 8 draws while copying files...?
JarredWalton - Tuesday, July 9, 2013 - link
I'll have to look into making more detailed graphs for the full review. Yes, throughput fluctuates a bit, and the slower connections tend to fluctuate even more. The AC Bridge does tend to be far more consistent in throughput than the other adapters. As for the 50 foot problem (sorry, that's 15.24m for the international audience...), that was more specifically a problem with the devices than with WiFi in general. I have one WiFi device (single stream 2.4GHz 802.11n) that can actually get amazing coverage. It lacks throughput, but for moderate traffic I think I can get well over 300 feet (100m) without dropping connectivity.Urbanos - Tuesday, July 9, 2013 - link
please add netgear, asus and engenius AC routers to your mix if you are going to do some reviews... and anyone else who might have them out by now/then. it would be good to offer some comparisons on range and performance from the low to the high end, as well as some tasks that traditionally weren't accessible or usable via wifi b/g/n that should be possible now via AC.JarredWalton - Tuesday, July 9, 2013 - link
I will have to see who is interested in sending routers for review -- would like to get an AirPort Extreme tossed into the mix as well, but TBH I'm not interested in buying any of the routers with my own money. :-)ikjadoon - Tuesday, July 9, 2013 - link
Well, then, this suggestion might be pointless. But, I have a heard of a number of system administrators recommend Ubiquiti routers as great medium-business routers. It's a hefty $340 for their AC-router, the UniFi, but if you're going through a handful of routers in a few years, maybe it's worth it! :DJarredWalton - Tuesday, July 9, 2013 - link
Interestingly enough, they just emailed me and asked to send their AC access point. :-)DanNeely - Tuesday, July 9, 2013 - link
Cool. I'm definitely interested to see if they bring anything to the table beyond enhanced tools for managing a number of access points in a network.miahshodan - Tuesday, July 9, 2013 - link
I keep reading how great 5ghz is. But the reality in my house I often can't connect at all on 5ghz while 2.4 is fine. I think it all comes down to environment. For larger houses in non-crowded areas 2.4 ghz can be superior. Hopefully AC will help with the 5ghz range. You almost need two or three test area scenarios to account for different distances, construction techniques, wireless traffic scenarios etc.