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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lordbannon - Monday, July 8, 2013 - linkI've had two wireless ac routers working as a bridge between the two main network nodes in my house for a few months, and while the latency clearly isn't quite there yet, for file transfers I'm not really seeing any issues. Its the first time I've actually not been concerned with getting around to wiring my house!
DaveLessnau - Tuesday, July 9, 2013 - linkI've got Netgear R6300s in two rooms configured in Bridge Mode to my original R6300 (configured as a regular Access Point) using 5GHz. Transferring files across the LAN (i.e., from an SSD in the Windows 8 computer on one Bridge to the SSD in the Windows 7 computer on the other Bridge) doesn't seem very good to me. My speeds (according to Windows) are:
- a single 2.69 GB file transferred at 14.2 MB/s (114 Mbps).
- 1,223 items totaling 2.93 GB transferred at just about the same speed (13.2 MB/s or 106 Mbps).
That's about half the real-world speed I'd expect transferring to a slow USB 2.0 drive. Considering that all of these R6300s are 802.11ac devices, I'd have expected at least two or three times that speed.
Guspaz - Tuesday, July 9, 2013 - linkI get better speeds out of my 2x2 802.11n network...
Spoelie - Tuesday, July 9, 2013 - linkDo all the R6300s use the same channel? Potential for interference there. Max speed you will only see when there's only one client actively sending on the network, no competing networks on the same channel and the other client is wired to the AP.
DaveLessnau - Tuesday, July 9, 2013 - linkUnfortunately, as far as I can tell, the R6300s in Bridge Mode can't specify their channel. The channel is set in the Access Point router and whatever it's set to is what all the bridges use. It looks like the only way to specify different channels for each bridge is to have one of the bridges use 2.4GHz and have the other use 5GHz. One of these days, I'll get around to testing how that works. But, still, these R6300s are supposed to be capable of 1300 Mbps. Channel conflict or not, I really expected better than 8% of the rated speed.
DaveLessnau - Tuesday, July 9, 2013 - linkOops. I forgot to mention that there aren't any other 5GHz networks in the area. Actually, there's only one other 2.4GHz network that's within range. That's a nice benefit of living in a standalone house in a neighborhood populated mostly by little ol' ladies. :)
virgahyatt - Thursday, July 25, 2013 - linkIf they are acting as wireless bridges then you can't set different channels. However there is no interference issue in that scenario. Though wireless bridging increases overhead and therefore slows down your actual transfer speed.
0ldman79 - Thursday, July 11, 2013 - linkNetgear may be your problem. I've never had any luck with Netgear routers for myself or any of my customers.
Linksys/Cisco seem OK, but the almost exclusive use of Broadcom chips limit them.
Atheros makes some really nice chipsets, but they don't have good market penetration in consumer level equipment.
I've got quite a bit of Atheros equipment in the air and I've done quite a bit of testing. Atheros beats just about every one else in range and throughput.
Mokona512 - Friday, August 16, 2013 - linkWhat router companies usually fail to mention is that high speed wifi are broken up into multiple streams.
the problem with this is that network applications which only make 1 connection, will only use a single stream.
This means that in order to reach your full speed, you need to get 3-4 connections going.
you can easily test this yourself, on your network create an FTP server or any other basic server that you can download files from
Then use a download manager such as down them all for firefox. then have it download and compare your speeds.
with 802.11ac, speeds quickly drop with distance because it can not maintain something as high as 256QAM for more than a few feet. and generally after about 20 feet, each stream will give around 100-120mbit/s of performance.
At best, wifi only offers around 40-50% of the advertised speed It has been this way since 802.11g (802.11b offers over half, you could expect around 8-9mbit/s on an 11mbit connection)
windows file transfer will often only make 1 connection but depending on the router, different streams can take turns handling a single connection which leads to a small speed boost, but nothing close to a true multi connection.
The good thing about the r6300 is that is has very high end wifi radios and they can be heavily optimized so netgear may release more updates to further optimize the wifi, or the community behind tomato or some other open firmware, will implement some of the latest optimizations.
PS if just having a slower client connected to the 5GHz network will slow the 5GHz network down or cause the router to drop to an N450 mode, so if you have 1 router set up as a bridge and the main router set up as normal where the second router shows up as a client, then make sure no non ac1300 client is connected to the 5GHz.
If the network has to compensate for a slower client then it also disables all AC tailored optimizations.
SlyNine - Saturday, January 10, 2015 - linkI do not believe that last part to be true. Ac afaik will stay at ac speeds even with an n device.
You really need to site some sources, because I'm calling bs on most of your rant.