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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JarredWalton - Wednesday, July 10, 2013 - link
One should be on the way (or I think it might be the newer model).ddriver - Wednesday, July 10, 2013 - link
No latency test? Really?JarredWalton - Wednesday, July 10, 2013 - link
Did you read the part in the article where I said, "This is a shorter introductory piece, so don’t expect a full suite of benchmarks..." I guess not.This was not intended to be a full review, but just to show that AC can be quite useful, and that we're working on testing some AC routers (which is in part a way of sending out a fishing line for additional products -- I've got two more coming already). The full review will look at latency, consistency of connection, and Rx/Tx speeds under more than one workload and at more than one location. Stay tuned....
ddriver - Wednesday, July 10, 2013 - link
Well, it is not like pinging is very challenging or time consuming, but whatever. Hopefully the full review will also include multiplayer gaming as well as other less typical workloads and naturally CPU load.JarredWalton - Wednesday, July 10, 2013 - link
Gaming is basically out, as I don't have the necessary equipment to test every single combination with the various WiFi adapters. I could test one adapter on one system with multiple routers, but most laptops have a whitelist of supported WiFi cards in their firmware so swapping cards in/out of a system doesn't generally work (and even if it does work with some, I'm not ready to tear apart someone's notebook review unit to accomplish the necessary testing).Please keep in mind that "comprehensive" looks at a technology can end up scaling the amount of testing time rapidly. If you have four routers and six adapters, you're already looking at 24 combinations to test. Now add in two more test locations and you get 96 combinations! Just the one "simple" test conducted in this article at two locations required a full day of testing to complete. Adding latency, copying lots of smaller files, then do the copy to the server rather than from the server (testing transmit rather than receive), and add in two more test locations to get an idea of how things look at 50' and 75', and I'm easily looking at a week or two dedicated purely to testing WiFi.
Simply put: I have a lot of other stuff on my plate, and while WiFi is definitely interesting, at some point I need to draw the line on what's in and what's out and write about the experience. My plan for now is to start with one router and several adapters (plus the bridge). Review that, then if everything checks out I can do the same tests on another router and so on. And in the meantime, I have a couple laptop reviews to complete, plus some other items as well, and a summer vacation to take. It might be a while before I'm done with this. :-)
kenthaman - Wednesday, July 10, 2013 - link
You should add the Ubiquity UniFi UAP-AC to your wifi testbed. I'd really like to see how their numbers rate compared to the other devices you've tested.JarredWalton - Wednesday, July 10, 2013 - link
We should be getting the UniFi 3.0 for testing as well.fc528e - Wednesday, July 10, 2013 - link
Very nice comprehensive review of 11ac as it currently stands! I'm really glad you were able to compile these results from an array of devices. Sounds like a worthy upgrade (assuming good hardware on the receiving end is there).Laststop311 - Wednesday, July 10, 2013 - link
I'll never give up my wired gbit connection. It's much easier knowing when the net messes up that you know its not the connection to the comp. And when you reformat the intel ethernet nic's just kinda work wifi gotta find drivers. I can see changing to 10gbit wired when that penetrates the consumer space. Especially with ssd's really need the bandwidth. SSD's are basically bottlenecked by the 6 gbps sata III limitation (the top ssd's at least). So hopefully 10gbit ethernet will be standard when sata express is standard. Wired is lower latency as well. People can't hack into it with a laptop parked in front of your house and steal bandwidth and do illegal stuff, neighbors can't hack it and mooch free internet off you. And there is still a ton of value in houses coming pre ethernet wired with ports in every room. I know that will be a requirement usb 3.0 ports and 10gbit ethernet ports with the power jacks in the next house i buy.HisDivineOrder - Thursday, July 11, 2013 - link
It's sad. I haven't seen a router that compelled me since my DIR-655. Years and years now. It isn't even that good, requiring reboots every month or so. I don't trust the new firmwares they put out any more and perhaps the new wireless hotness would be nice, but the truth is I don't feel like throwing down another $50-200 for the new hotness and have it be same as the old hotness with a slightly faster speed.Gigabit is all I need. I've been vaguely tempted by the faster processors and greater memory in recent Asus routers, but this article shows when you get outside of the same room, wireless starts to show only very narrow differences.
And latency still sucks. For the same reason I don't use wireless keyboards and mice for my everyday system is the same reason I wouldn't use wireless networking on my everyday system.
That said, having wireless is better than not just for the option. Until tablets, smartphones, consoles, laptops, and everything else use the NEW wireless spec (and it becomes officially released instead of a beta), there's just no reason to buy in yet.
By the time they finally get around to putting out affordable Nexus-class devices with it integrated and iPad's with it and most laptops have it, we should have cheaper and better routers with it, too.