WiFi & GPS

The WiFi stack gets an update with the new iPad courtesy of Broadcom's 65nm BCM4330, compared to the BCM4329 used in the previous two iPads. Both 2.4GHz and 5GHz operation are supported, although as I mentioned earlier the carrier-dependent personal hotspot is only available over 2.4GHz.

As with most smartphone/tablet designs the BCM4330 only supports a single spatial stream, for a maximum link speed of 72Mbps. Similar to the iPad 2, Apple hides the WiFi antenna behind the speaker grille at the bottom of the tablet. The cellular antennas (there are now two) are at the top of the tablet, behind the plastic RF window.

WiFi Performance Comparison
Distance from AP 3 feet 20 feet (Different Room) 50 feet (Different Room/Floor) 100 feet (Different Room)
ASUS TF Prime (2.4GHz) 26.9 Mbps 9.85 Mbps 13.5 Mbps 2.20 Mbps
Apple iPad 2 (2.4GHz) 35.1 Mbps 29.9 Mbps 26.9 Mbps 10.6 Mbps
Apple iPad 3 (2.4GHz) 35.1 Mbps 29.9 Mbps 27.9 Mbps 9.98 Mbps
Apple iPad 2 (5GHz) 36.7 Mbps 36.7 Mbps 36.7 Mbps 11.9 Mbps
Apple iPad 3 (5GHz) 36.7 Mbps 36.7 Mbps 36.7 Mbps 11.7 Mbps

With a similar WiFi stack and similar antenna placement, it's no surprise that I noticed very similar WiFi performance to the iPad 2.

The same goes for GPS performance between the new iPad and the iPad 2. Both devices were able to lock and track me driving around in a car with comparable accuracy from what I could tell.

Airplay Support with the new Apple TV

When paired with a second or third generation Apple TV, the iPad supports wireless display mirroring or content streaming to the iPad via AirPlay. In other words, if you have an Apple TV hooked up to your HDTV, you can use your HDTV as a large, mirrored, secondary display for your iPad—wirelessly. The only requirement is that you have a 2nd or 3rd generation Apple TV and that it's on the same network as your iPad. With those requirements met, enabling AirPlay mirroring is simple—just bring up the iOS task switcher, swipe left to right until you see the brightness/playback controls and tap the AirPlay icon.

Mirroring gives you exactly what you'd expect—a complete mirror of everything you see on the local iPad screen. All sounds are also sent over and come out via your TV's speakers—the local speaker remains silent.

The frame rate isn't as high on the remote display, but there's virtually no impact to the performance of the iPad itself. There's noticeable latency of course since the display output is transcoded as a video, sent over WiFi to the Apple TV, decoded and displayed on your TV via HDMI. I measured the AirPlay latency at ms, which is reasonable for browsing the web but too high for any real-time games. If you want to use the iPad to drive your HDTV for gaming you'll need to buy the optional HDMI output dongle.

While AirPlay mirroring on the iPad works at 720p, if you're playing a 1080p movie on the new iPad and you have a 3rd generation Apple TV, the video is also displayed in 1080p rather than downscaled to 720p.

Video playback is an interesting use case for AirPlay and the iPad. If you don't have mirroring enabled, you can actually start playing a movie on the iPad, have it stream to your TV via the Apple TV, and go about using your iPad as if nothing else was happening. Most apps will allow you to stream video in the background without interrupting, however some games (e.g. GTA 3, Infinity Blade 2) and some apps (e.g. iMovie) will insist on streaming their UI to your Apple TV instead.

Although iOS and the iPad don't do a great job of promoting multi-user experiences, using AirPlay to push video to a TV wirelessly is an exception. If you frequently load your iPad up with movies you can use it to keep others entertained while you either get work done or just goof around on your iPad at the same time. It's a great fit for families where people want to do two different things. If you do put a lot of movies on your iPhone/iPad, the 3rd generation Apple TV is probably a must buy for this reason alone.

Gaming Conclusion & Controller Support: An Android Advantage What's Next: 6th gen iPhone, Haswell & Windows 8
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  • name99 - Friday, March 30, 2012 - link

    Just to clarify, this is NOT some Apple proprietary thing. The Apple ports are following the USB charging spec. This is an optional part of the spec, but any other manufacturer is also welcome to follow it --- if they care about the user experience.
  • darkcrayon - Thursday, March 29, 2012 - link

    All recent Macs (last 2-3 years) can supply additional power via their USB ports which is enough to charge an iPad that's turned on (though probably not if it's working very hard doing something). Most non-Mac computer USB ports can only deliver the standard amount of USB power, which is why you're seeing this.

    Your Lenovo *should* still recharge the iPad if the iPad is locked and sleeping, though it will do so very slowly.
  • dagamer34 - Friday, March 30, 2012 - link

    I did the calculations and it would take about 21 hours to recharge an iPad 3 on a normal non-fast charging USB port from dead to 100%. Keep in mind, we're talking about a battery that's larger in capacity than the 11" MacBook Air.
  • snoozemode - Thursday, March 29, 2012 - link

    http://www.qualcomm.com/media/documents/files/snap...
  • Aenean144 - Thursday, March 29, 2012 - link

    Anandtech: "iPhoto is a very tangible example of where Apple could have benefitted from having four CPU cores on A5X"

    Is iPhoto really a kind of app that can actually take advantage of 2 cores? If there are batch image processing type functionality, certainly, though I don't know if iPhoto for iOS has this type of functionality. The slowness could just be from a 1.0 product and further tuning and refinement will fix it.

    I'm typically highly skeptical of the generic "if the app is multithreaded, it can make use of all of the cores" line of thought. Basically all of the threads, save one, are typically just waiting on user input.
  • Anand Lal Shimpi - Thursday, March 29, 2012 - link

    It very well could be that iOS iPhoto isn't well written, but in using the editing tools I can typically use 60 - 95% of the A5X's two hardware threads. Two more cores, at the bare minimum, would improve UI responsiveness as it gives the scheduler another, lightly scheduled core to target.

    Alternatively, a 50% increase in operating frequency and an improvement in IPC could result in the same net benefit.

    Take care,
    Anand
  • shompa - Friday, March 30, 2012 - link

    *hint* Use top on a iOS/Android device and you will see 30-60 processes at all time. The single threaded, single program thinking is Windows specific and have been solved on Unix since late 1960. Todays Windows phones are all single threaded because windows kernel is not good at Multit hreding.

    With many processes running, it will always be beneficial to have additional cores. Apple have also solved it in OSX by adding Grand central dispatch in their development tools making multithreaded programs easy.

    Iphoto for Ipad: Editing 3 million pixel will demand huge amount of CPU/GPU time + memory. Apple have so far been able to program elegant solutions around the limits of ARM CPUs by using NOVA SIMD extensions and GPU acceleration. An educated guess is that Iphoto is not fully optimized and will be at later time.

    (the integrated approach gives Apple a huge advantage over Android since Apple can accelerate stuff with SIMDs. Google does not control the hardware and can therefore not optimize its code. That is one of the reasons why single core A4 was almost as fast as dual core Tegras. I was surpassed when Google managed to implement their own acceleration in Andriod 4.X. Instead of SIMD, Google uses GL, since all devices have graphics cards. This is the best feuture in Android 4.x.)
  • name99 - Thursday, March 29, 2012 - link

    [/quote]
    Apple’s design lifespan directly correlates to the maturity of the product line as well as the competitiveness of the market the product is in.
    [/quote]

    I think this is completely the wrong way to look at it. Look across the entire Apple product line.
    I'd say a better analysis of chassis is that when a product first comes out, Apple can't be sure how it will be used and perceived, so there is some experimentation with different designs. But as time goes by, the design becomes more and more perfected (yes yes, if you hate Apple we know your feelings about the use of this word) and so there's no need to change until something substantial drives a large change.

    Look, for example, at the evolution of iMac from the Luxo Jr version to the white all-in-on-flatscreen, to the current aluminum-edged flatscreen which is largely unchanged for what, five or six years now. Likewise for the MacBook Pro.
    Look at the MacBook Air. The first two revs showed the same experimentation, trying different curves and angles, but Apple (and I'd say customers) seems to feel that the current wedge shape is optimal --- a definite improvement on the previous MBA models, and without anything that obviously needs to be improved. (Perhaps the sharp edges could be rounded a little, and if someone could work out the mechanicals, perhaps the screen could tilt further back.)

    And people accept and are comfortable with this --- in spite of "people buy Apple as a fashion statement idiocy". No-one will be at all upset if the Ivy League iMacs and MBAs and Mac Minis look like their predecessors (apart from minor changes like USB3 ports) --- in fact people expect it.

    So for iPhone and iPad. Might Apple keep using the same iPhone4 chassis for the next two years, with only minor changes? Why not? There's no obvious improvement it needs.
    (Except, maybe, a magnet on the side like iPad has, so you could slip a book-like case on it that covered the screen, and switched it on by opening the book.)
    Likewise for iPad.

    New must have features in phones/tablets (NFC? near-field charging? waterproof? built-in projector like Samsung Beam?) might change things. But absent those, really, the issue is not "Apple uses two year design cycles", it is "Apple perfects the design, then sticks with it".
  • mr_ripley - Thursday, March 29, 2012 - link

    "In situations where a game is available in both the iOS app store as well as NVIDIA's Tegra Zone, NVIDIA generally delivers a comparable gaming experience to what you get on the iPad... The iPad's GPU performance advantage just isn't evident in those cases..."

    Would you expect it to be if all the games you compare have not been optimized for the new ipad yet? They run at great frame rates but suffer in visuals or are only available at ipad 2 resolutions. The tegra zone games are clearly optimized for Tegra while their iOS counterparts are not optimized for the A5x, so of course the GPU advantage is not evident.

    This comparison does not seem fair unless there is a valid reason to believe that the tegra zone games cannot be further enhanced/optimized to take advantage of the new ipad hardware.

    I suspect that the tegra zone games optimized for A5x will offer a tangibly superior performance and experience. And the fact that the real world performance suffers today does not mean we will not see it shortly.
  • Steelbom - Thursday, March 29, 2012 - link

    Exactly this.

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