The 2013 MacBook Air Review (13-inch)
by Anand Lal Shimpi on June 24, 2013 12:01 AM EST802.11ac: 533Mbps Over WiFi
Haswell isn’t all that’s new with the 2013 MacBook Air, Apple also integrated support for 802.11ac. I wrote a primer on 802.11ac last year, but I’ll provide a quick recap here. 802.11ac is a 5GHz-only WiFi standard, with support for wider channels (80/160MHz vs. 40MHz in 802.11n) and better spatial efficiency within those channels (256QAM vs. 64QAM in 802.11n). Today, that means a doubling of channel bandwidth and a 4x increase in data encoded on a carrier, which are responsible for the significant increase in bandwidth. Usable bandwidth should also see improvements on 802.11ac as high-end access points are all expected to ship with beam forming enabled.
The first 802.11ac implementations we saw were on the smartphone side with HTC’s One and Samsung’s Galaxy S 4. Both of these devices were single antenna/single spatial stream implementations with 80MHz channels and 256QAM, resulting in a max PHY rate of 433Mbps. In his review of the HTC One, Brian documented peak performance using iPerf and a TCP transfer. In a smartphone, such high bandwidth from WiFi is really useful for improving battery life (race to sleep). In a notebook, you get the same potential improvement in battery life but there’s one more: a wireless alternative to Gigabit Ethernet.
In a 3-stream configuration given what’s available today, we’re talking about a 1.33Gbps PHY rate. Assuming better link efficiency on a notebook compared to what we’ve seen in smartphones thus far, we could be talking about a real alternative to Gigabit Ethernet - at least close to an AP. While wired GbE is always going to give you a more consistent experience, the vast majority of homes aren’t pre-wired with Gigabit Ethernet. In living situations where you can’t just run a bunch of Cat6 everywhere, but still want high speed networking, 802.11ac could be a real alternative.
The 2013 MacBook Air adds support for 802.11ac via Broadcom’s BCM4360. The controller is capable of supporting up to 3 spatial streams, but in its implementation in the MacBook Air we see a maximum of 2 used. I fully expect the 2013 rMBPs to use a third antenna to leverage all 3 streams. BCM4360 supports 80MHz channels, 256QAM and short guard intervals. The result is a max PHY rate of 867Mbps.
ASUS sent me its RT-AC66U based on the same BCM4360 silicon (coincidentally the same controller that’s in the new Airport Extreme), which I promptly used for testing the new MacBook Air. The ASUS router and MacBook Air combination worked perfectly. In the same room as the AP, I had no issues seeing the maximum 867Mbps PHY rate (above).
Within about 5 - 8 feet of the AP, I saw an average of 533Mbps using iPerf. That’s real data sent over TCP:
A 3-stream solution could definitely rival wired GbE, at least for short distances.
I then went about characterizing 802.11ac performance vs. distance to get an idea for how performance fell off as I moved away from the AP. My desk and test area is in the corner of my office, which is where I put the ASUS 802.11ac router. Performance around my desk was always up around 533Mbps.
Move around 18 feet away but remain in the same room and measured performance dropped to 450Mbps. One set of walls and another 10 - 15 feet dropped performance to between 250Mbps - 340Mbps. Another set of walls without moving much further and I was looking at 200Mbps. When I went one more set of rooms away, or dropped down to a lower level, I saw pretty consistent falloff in performance - dropping down to 145Mbps. Note that my setup is pretty much the worst case scenario for longer distances. The AP isn’t centrally located at all. If I were setting up an 802.11ac network for max coverage, I’d probably see 300 - 400Mbps in most immediately adjacent rooms.
So 802.11ac on the new MacBook Air is pretty awesome, there's just one issue...
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appliance5000 - Friday, December 20, 2013 - link
One word - tablets.mikeztm - Monday, June 24, 2013 - link
Could that PCIe ssd works with Filevault2 without performance down?My 2011 MBA's SSD became much slower after enabling Filevault2.
|-8-| - Monday, June 24, 2013 - link
>Five years after its introduction, the MacBook Air really has>grown into a very polished, mature platform. The 2013
>model is really the epitome of what Apple set out to
>build back in 2008, we just finally have the right hardware
>available to realize the vision. Nearly every component has
>been perfectly selected.
For a ultramobile working horse, there are still some substantial shortcomings: It's still a glossy display tying your work place to indoor use or cloudy weather. There is still no LAN, no VGA - this makes many headaches in business everyday life.
Maybe the author better leaves the marketing to Apple and concentrates on listing the Pros AND Cons of the product. It's a fine notebook, but definitely not perfect. ;)
weiran - Monday, June 24, 2013 - link
You forget not everyone works in a corporation and has your requirements, especially considering this is a consumer device first and foremost. Apple looks to the future, which may mean minor pain in the short-term (having to use adapters for LAN and VGA), but realistically do you think in 2-3 years either of those will exist on any consumer laptop?|-8-| - Monday, June 24, 2013 - link
It's not about having these or that requirements. The author is praising something to the skies, that has obvious short comings. (Every product has that.) What would be more 'neutral' verbalised: The components are perfectly selected. [...]. There are a few compromises, so the screen has good contrast, but isn't really usable outside, for example in a park. Further missing legacy ports force to carry adapters for using old legacy infrastructure like LAN networks or common LCD projectors.It's about writing a review - I don't want to read someones marketing arguments.
And by the way: Yes, VGA and LAN will be important in the future - most LCD projectors still have VGA and in contrast to HDMI or Displayport it really works reliable. I was at a conference a month ago - VGA saved me as Displayport wasn't working at all.
LAN is without alternative to share and synchronise big amounts of data.
Grennum - Monday, June 24, 2013 - link
VGA is certainly dying. By the end of the year all of the projects in our boardrooms will be replaced with Smart Screens, which you connect to via Wi-Fi. We have wired HDMI as a back-up works perfectly.Wired LAN is not dying by why would you ever have large amounts of data on your ultra portable laptop? That is just be irresponsible. If you are working with large data sets best to do it on a remote system where you have the performance, and reliability.
This laptop would perfectly meet the needs for many of our business users, maybe not engineering, but then engineering wouldn't be looking at an ultraportable (remote engineering desktops notwithstanding)
|-8-| - Monday, June 24, 2013 - link
Maybe I should switch to your company. ;) There are some new projectors here having HDMI (sadly no Displayport). But most projectors are quite old (still working), these are connected via VGA. There is some time left, till the last old projectors die.Honestly I don't see a bonus in digital alternatives. THE standard is still missing, as most notebooks have either HDMI or Displayport.
WLAN seems to have high signal latency between two computers. If you syncronise two big collections of many many subfolders and many small files in there, you notice a huge difference even between 100 MBit/s LAN and 300 MBit/s WLAN. I use WLAN for backups, but speed sucks.
Another problem is security of data in the private sector, these security guys don't like WLAN.
A5 - Monday, June 24, 2013 - link
Then maybe don't work in a park? I don't know of any laptop with a bright enough screen and good enough battery life to actually work outdoors.|-8-| - Monday, June 24, 2013 - link
Well, the Samsung Series 9 900X3C-A04DE or the Lenovo x220/x230 are two, that can be used outdoors. There should be more, some Zenbooks have also matte screens.darwinosx - Monday, June 24, 2013 - link
Well Samsung makes cheap junk that doesn't work and has no support.