Usability & iOS 7

The iPad Air remains one of the best consumer tablet experiences around. The OS and Apple’s first party applications are both extremely well suited to the tablet, and there’s a very healthy ecosystem of third party applications to fill in the gaps left by Apple.

Lately Apple has been doing wonders to limit those gaps. Both iLife and iWork suites are now free with the purchase of any new iOS 7 device, including the iPad Air. Previously each of the three iLife apps set you back $5 a piece ($15 total), while the iWork apps were priced at $10 a piece ($30 total). Apple has truly embraced its role as a devices and software company and is using the latter to help sell the former. On the one hand this is an admission that the market is growing more competitive, as tossing in free software is a great differentiator. On the other hand, freeing up iLife/iWork is a vote of confidence in Apple’s ability to continue to demand a premium for its hardware. Neither suite comes preinstalled on the iPad Air, but upon a visit to the App Store users are reminded that they can get all six of the apps for free if they should desire to. I suspect part of the reason that they’re not bundled by default is to avoid eating up space on the devices with less NAND by default.

The core iOS apps are quite approachable and easy to use. Applications like Safari and Mail make great use of the high resolution screen. Obviously the same can be said for things like Photos and iPhoto. The virtual keyboard experience is great on the large display (especially in landscape mode). Honestly, if there was a good Google Hangouts app (the Android version is much better in my experience) for iOS 7 I think I could be very comfortable and productive on the iPad Air.

I find that task switching is far better on the iPad than it is on the iPhone since multitasking gestures are supported. A four finger swipe left/right between applications or up/down to bring up the task switcher is so much quicker for me than a double tap of the physical home button. Similarly a five finger pinch to get back to the home screen from any application is significantly faster. The new iOS 7 multitasking UI feels so much more at home on the iPad’s large display as well.

My only complaint about task switching on the iPad Air is that UI frame rate will regularly drop below 30 fps during some of these transitions. The added GPU performance on the A7 doesn't seem to really impact things compared to the A6X, so I’m fairly convinced at this point that the solution to the problem will have to come in software. It’s quite reminiscent of the Retina MacBook Pro UI frame rate issues under Mountain Lion, although not nearly as bad (and I’m hoping it won’t take a year to get these ones resolved).

The release of iOS 7.0.3 addressed (at least partially) some of my concerns around the OS. As I already mentioned, stability on 64-bit platforms seems somewhat improved - at least compared to the initial release of iOS 7. The other big improvement in my mind is the ability to turn off/reduce the transition animations. The impact to usability on the iPhone 5s is huge, but it’s also pretty significant on the iPad Air. The animations themselves are pretty but I find that they get repetitive after continued use.

Memory Size & The Impact of 64-bit Applications

The iPad Air, like the iPhone 5s, ships with 1GB of LPDDR3 memory. Apple frowns upon dissection of review samples but I think it’s a safe bet that we’re not talking about a PoP (Package-on-Package) configuration but rather discrete, external DRAM here. It’s also probably a safe bet that even the iPad mini with Retina Display will ship with 1GB of memory as well.

Something I didn’t have time to address in my iPhone 5s review was the impact of 64-bit applications on memory usage. I actually ran some tests after the 5s review hit but never got the chance to share the data, so I figured now is as good a time as any to do just that.

Unlike traditional desktop OSes, iOS doesn’t support paging to disk (or in this case, NAND). Application data can either reside in memory or the associated process is terminated and has to be reloaded the next time you request it. It’s a decision likely made to both maintain user experience and limit the number of program/erase cycles on the internal NAND.

The good news is that iOS was architected to run on as little hardware as possible and as a result tends to be quite memory efficient. There are also power implications of going to larger memories. The combination of these two things has kept Apple on the conservative side of increasing memory capacity on many iDevices.

The move to a 64-bit platform however does complicate things a bit. Moving to a larger memory address space increases the size of pointers, which in turn can increase the footprint of 64-bit applications compared to their 32-bit counterparts. So although there’s clearly a performance uplift from app developers recompiling in 64-bit mode (more registers, access to new instructions), there’s also an associated memory footprint penalty. Since the iPad Air and iPhone 5s don’t feature a corresponding increase in memory capacity, I wondered if this might be a problem going forward.

To find out I monitored total platform memory usage in a couple of scenarios. Before measuring I always manually quit all open apps and performed a hard reset on the device. Note that the data below is reporting both clean and dirty memory, so it’s possible that some of the memory space could be recovered in the event that another process needed it. I hoped to minimize the impact by always working on a cleanly reset platform and only testing one app at a time.

I looked at memory usage under the following scenarios:

1) A clean boot with no additional apps open
2) Running Mobile Safari with 4 tabs open (two AnandTech.com tabs, two Apple.com tabs, all showing the same content)
3) Infinity Blade 3 (64-bit enabled) sitting at the very first scene once you start the game
4) iOS Maps in hybrid view with 3D mode enabled, with a WiFi assisted GPS lock on my physical location
5) Google Maps in the same view, under the same conditions. I threw in this one to have a 32-bit app reference point.

In general you’re looking at a 20 - 30% increase in memory footprint when dealing with an all 64-bit environment. At worst, the device’s total memory usage never exceeded 60% of what ships with the platform but these are admittedly fairly light use cases. With more apps open, including some doing work in the background, I do see relatively aggressive eviction of apps from memory. The most visible case is when Safari tabs have to be reloaded upon switching to them. Applications being evicted from memory don’t tend to be a huge problem since the A7 can reload them quickly.

The tricky part is you don’t really need all that much more memory. Unfortunately as with any dual-channel memory architecture, you’re fairly limited in how you can increase memory capacity and still get peak performance. Apple’s only move here would be to go to 2GB, which understandably comes with both power and financial costs. The former is a bigger concern for the iPhone 5s, but on the iPad Air I would’ve expected a transition sooner rather than later.

Although things seem to have improved with iOS 7.0.3, the 64-bit builds of the OS still seem to run into stability issues more frequently than their 32-bit counterparts. I still see low memory errors associated with any crashes. It could just be that the move to 64-bit applications (and associated memory pressure) is putting more stress on iOS’ memory management routines, which in turn exposes some weaknesses. The iPad Air crashed a couple of times on me (3 times total during the past week), but no where near as much as earlier devices running iOS 7.0.1.

Battery Life Final Words
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  • over9k - Tuesday, October 29, 2013 - link

    Two paragraphs in and this is already better than all the other "reviews" out there. Reply
  • Beautyspin - Tuesday, October 29, 2013 - link

    You should not really call any review by Anandtech of Apple products as reviews. They are homages paid to their shrine. This is a ritual with them.. Reply
  • Drumsticks - Tuesday, October 29, 2013 - link

    I always hear people complaining about bias here and elsewhere for apple products. But what exactly is the reason for that? The majority of the review is seriously objective - you can't argue that apple has some of the best performance in he game right now, and the best display to boot. He only thing rivaling it is probably the higher clocked Z3770, while Qualcomm will probably pass Apple's GPU early next year.

    as far as subjectivity goes, even if you don't like the design, the materials are solid. And it manages to be lighter than every other ten inch tablet on the market (and thinner) withot sacrificing battery life. The only subjective things I could possibly see are maybe the sound quality and the OS itself, of which he criticized a few times. Where does the bias come in?
    Reply
  • Fleeb - Tuesday, October 29, 2013 - link

    "and the best display to boot"

    We have yet to wait for the Kindle HDX review but it is lighter, packs more pixels and with 100%RGB gamut.
    Reply
  • darwinosx - Wednesday, October 30, 2013 - link

    Its lighter because it is cheap plastic. It is also a far more limited device. Really laughable to think it compares to an Air. Reply
  • dsumanik - Wednesday, October 30, 2013 - link

    Read this review with a grain of salt. Anand lai shimpi is heavenly vested in apple stock, doing everything he can to boost the dismal situation.

    Thinner bezels and light weight do not hide the fact that functionally, this iPad is the same as the previous 2 generations.

    Sent from my ipad3, which will be upgraded when apple actually updates the product line.

    Here's some basic ideas mr cook:

    Wireless charging
    Fingerprint scanner
    Thunderbolt sync or usb3
    Haptic feedback
    NFC
    Reply
  • John2k13 - Wednesday, October 30, 2013 - link

    You know what's disgusting about your comment, and those similar to yours? That you basically accuse the author of being a liar, a shill, and completely lacking in integrity- without a shred of evidence. I read the entire 10 page review, and it was incredibly detailed, precise, and well-written, something that would be obvious to most sane, rational, objective people.

    "Anand lai shimpi is heavenly vested in apple stock, doing everything he can to boost the dismal situation."

    First of all, what "dismal situation"? Apple stock is up around $130 from a few months ago, or almost a third. Hardly "dismal". Also, do you think a single review from a website visited primarily by tech geeks is going to have any fucking effect on the stock? I mean, are you for real? Don't assume the author holds the same amount of ignorant stupidity that you apparently do, to think for a second this review would have a snowball's chance in hell in affecting stock. You clearly know nothing about how the financial market works.

    "Thinner bezels and light weight do not hide the fact that functionally, this iPad is the same as the previous 2 generations."

    Functionality on a tablet is primarily based on software, and the iPad has 475,000+ optimized apps which are getting more powerful all the time. The hardware simply enables better software. A tablet is basically a blank slate for the software, and better hardware helps in enabling better software. Every single aspect of this iPad is improved, so yes, it is more "functional". That list you made, though, is pretty ridiculous, and obviously a desperate attempt to list anything you can think of that the iPad doesn't have and pretend its significant.

    Wireless charging- why? This makes the device more functional, how?
    Fingerprint scanner- Wow, brilliant "idea". You probably mocked touch ID when it appeared on the 5S. Again, this would be nice to have I guess, but in no way impedes "functionality" of the tablet.
    Thunderbolt sync or usb3- I have no idea what "thunderbolt sync" means, and its pretty ridiculous you're harping on a USB3 port. It will never happen, nor should it.
    Haptic feedback- Utterly useless gimmick, but heym why not, right?
    NFC- I have NFC on my Nexus 4, and not ONCE have I even run into an opportunity or a reason to use it. But yeah, I'm sure you honestly think it's needed or useful on an iPad. Again, another meaningless bulletpoint you were desperate to add mindlessly.

    Next time you want to baselessly accuse an author of being a liar, a shill, a sellout, and having no honesty or integrity, try to make a coherent post that actually contains some intelligent, well thought out information. Otherwise, by attacking the author you just embarrass yourself as you did now. Grow up.
    Reply
  • ABR - Wednesday, October 30, 2013 - link

    Actually thunderbolt sync is one of the changes I'm really waiting for. Have you ever tried restoring even a 16GB iPad over USB? Slow agony. I can't even imagine what someone w/a 64 or 128GB model must go through. Even ordinary everyday syncs are far slower than what they could or should be. Reply
  • Howard Ellacott - Wednesday, October 30, 2013 - link

    You clearly don't realise what thunderbolt is, which is why that's such a stupid suggestion. Yes, faster syncs would be amazing, and restoring a 64gb iPhone is a right pain, but thunderbolt isn't the way. Reply
  • Kristian Vättö - Wednesday, October 30, 2013 - link

    USB 2.0 isn't the real bottleneck there, it's NAND. Most eMMC solutions can't even saturate the USB 2.0 link with sequential writes, so Thunderbolt or USB 3.0 would do absolutely. Reply

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