The Joys of 802.11ac WiFiby Jarred Walton on July 8, 2013 8:15 PM EST
Recap: 802.11ac Wireless Networking
We’ve had quite a few major wireless networking standards over the years, and while some have certainly been better than others, I have remained a strong adherent of wired networking. I don’t expect I’ll give up the wires completely for a while yet, but Western Digital and Linksys sent me some 802.11ac routers for testing, and for the first time in a long time I’m really excited about wireless.
I’m not a good representative of normal PC users, but it has been a long time, relatively speaking, since we first saw Draft-N wireless options—Gary Key (now with ASUS) wrote about it what seems like an eternity ago, and in Internet time I suppose seven years is pretty darn close. Granted, 802.11ac has really been “done” for about two years now, but the first laptops to arrive with 11ac adapters are less than a month old—up until now, 11ac has been almost exclusively used for routers and bridges.
Before I get into a few performance specifics of 802.11ac testing, let me start by saying what is bad with 802.11n. The single biggest issue for me is the lack of quality implementations in so many of our devices. If you look at Apple’s MacBook Pro offerings, they’ve all been 3x3:3 MIMO for several years, offering connection speeds of up to 450Mbps. The problem with that “up to 450Mbps” is that it’s influenced by several factors.
Of course you need to know what sort of signal quality you have, but by far the bigger issue is this: are you talking about 2.4GHz 802.11n or 5GHz 802.11n? If you’re talking about the former, you can pretty much throw any thoughts of 450Mbps out the window. The bigger problem with “up to 450Mbps” is that the vast majority of laptops and routers don’t offer such support; Apple's 3x3:3 dual-band implementation is better than 99% of Windows laptops (and yes, I just made up that statistic).
About a year ago, I reviewed a router and repeater from Amped Wireless and found them to be good if not exceptional products. Compared to most of the wireless solutions people end up with, they were a breath of fresh air and I’ve actually been using them for the past year with very few complaints. On the other hand, I’ve had dozens of laptops come and go during the same time frame. Can you guess what the most common configuration is, even on more expensive laptops? If you said “single-band 2.4GHz 1x1:1”, give yourself a cookie.
We’re thankfully starting to see more laptops with dual-band 2x2:2 implementations, but even when you get that there’s still a big difference in actual performance, depending on notebook design, drivers, and other “special sauce”. We’ll see this in the charts on the next page, and it’s often more a statement of a particular laptop’s wireless implementation as opposed to representing what you might get from a particular wireless chipset.
In my opinion, the great thing about 802.11ac then is that any product claiming 802.11ac compliance is automatically dual-band. 11ac actually only works on the 5GHz channels, so for 2.4GHz support it’s no better than existing 802.11n solutions, but it’s fully backwards compatible and, as we’ll see in a moment, you really don’t want to use 2.4GHz wireless networking unless you’re primarily concerned with range of the signal. This is a shorter introductory piece, so don’t expect a full suite of benchmarks, but let’s just cut straight to the chase and say that there are a lot of situations in which I’ve found 802.11ac to be substantially faster than 802.11n.
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thetoad30 - Thursday, July 11, 2013 - linkI think you are sorely mistaken with this article. Here's why:
802.11ac will combine up to three 80 mhz 5 GHz streams. As each channel is 20MHz, you're looking at four channels per stream, by three streams, meaning 12 channels being used by ONE router. Since there are only 21 channels right now, one router takes up more than half the available spectrum in the 5GHz channel.
Remember 11n in the 2.4 GHz spectrum? Why didn't anyone get 40MHz channels? Because there were only three non-overlapping channels in the spectrum, and the number of people using it meant that interference was all but impossible to avoid in common neighborhoods. 11ac just brings that problem to the 5 GHz channel.
Second, Apple doesn't allow 40MHz three stream mode in their 2.4 GHz band - you are limited to 2x2 at 270 mbps for the same reason I outlined above.
People think that the 5GHz spectrum is the answer for interference - and it was because it had so many options to choose from to limit interference - but now that you're combining channels and soaking up more bandwidth, it will soon be just like the 2.4 GHz fiasco.
Just thought you'd want readers to know this before pouring money into products that eventually will have the same problems as before.
JarredWalton - Thursday, July 11, 2013 - linkYou're right that the amount of spectrum/channels being used by one router is higher with 11ac, but what you're not mentioning is range. The biggest issue with 2.4GHz (and the reason no one is doing 900MHz WiFi these days) is that the range on 2.4GHz is much greater. With a moderate yard (0.14 acres or so), I don't see my 5GHz signal much beyond my property, if at all. Most people who want bandwidth are really only looking at bandwidth within their home, in which case 11ac can be an excellent solution. On 2.4GHz, I can at least "see" anywhere from eight to twelve networks from my house, and that makes it extremely difficult to get a 40MHz channel. 3x3:3 can still get better throughput than 2x2:2, thanks to the extra stream, but for shorter distances 5GHz 11n is often two or three times faster than 2.4GHz 11n, and 5GHz 11ac can be another doubling in performance over 5GHz 11n.
I'm not saying 11ac is for everyone, but if you want higher bandwidth within a more limited area, it can be awesome. 40MBps to my downstairs HTPC is nearly four times what I got with the Amped Wireless router/repeater combination, also functioning on 5GHz. (And on 2.4GHz, the Amped Wireless only managed 4-6MBps most of the time.)
thetoad30 - Thursday, July 11, 2013 - linkHuh. I had a whole comment block that explained the issues with 11ac and some errors in the article and it appears to have been deleted. I wasn't disrespectful or arrogant either. Wondering if censoring is happening or if my account is messed up?
thetoad30 - Thursday, July 11, 2013 - linkNever mind - apparently it's working now.
Micropterus - Thursday, July 11, 2013 - linkDid this Mythlogic Pollux 1613 happen to have the Samsung PM841 mSATA SSD? Preferably 512GB, that you could test, please? :)
trip1ex - Friday, July 12, 2013 - linkI just wired my house with Cat6. It isn't just about pure speed but latency for me. The WMC experience likes low latency.
Conficio - Friday, July 12, 2013 - linkWhat about bufferbloat testing? For many throughput is only half of the story, latency in Wifi solutions is a big, big issue as well. Could you please consider testing the bufferbloat behavior of these implementations? Also add the buffer characteristics, size in hardware/drive if possible.
theduckofdeath - Sunday, July 14, 2013 - linkYou seem to like Apple a lot. I mean, they're a nice company and all, but, I really think the majority would enjoy seeing references to stuff adopted by a wider demographics once in a while?
JarredWalton - Monday, July 15, 2013 - linkThe only Apple product in my house is an iPod Touch 4th Gen, and I didn't even buy that. However, I've handled enough Apple MacBook Pro laptops and iPads and iPhones to know that they make a good product. I personally don't like OS X, and I hate the elitist mentality that seems to pervade the Apple user base, but credit where credit is due: Apple has pushed the state of the art in many areas. Having a rabid cult following helps, sure, but if the iPhone, iPod, iPad, etc. had lousy hardware and software, none of the devices would have seen the success they've enjoyed. You pay through the nose on some of their products, but generally speaking at least you get a quality result...provided you prefer running OS X, of course.
misaki - Tuesday, July 16, 2013 - linkFor years I've had problems with wifi dropping out/crashing when doing lots of file transfers and requiring reboots of the laptop/router using many different chipsets. But every time I tried to google it, I could never find any meaningful conversation on it. It's nice to know I wasn't the only one with these problems.