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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  • StigtriX - Tuesday, November 12, 2013 - link

    Actually, the new Kindle 8.9 has at least as good a display as the iPad Air, if not better:

    "Amazon’s always touted the displays on its tablets, and the screen it’s using on the HDX 8.9 is a doozy. At a ridiculous 2560 x 1600-pixel resolution and 339ppi, it’s either higher-resolution or more pixel-dense than virtually any other tablet on the market. It also has great viewing angles, excellent color reproduction, and high brightness levels. It’s really just a great screen, whether you’re gaming, watching video, or reading text — it’s right up there with, if not better than, the Retina display on the iPad Air."
    - The Verge

    "While the speakers feel like something of an afterthought, Amazon is clearly waging a battle on the display front. The company keeps upping its game, and indeed, the screen here dazzles, with 2,560 x 1,600 resolution and a pixel density of 339 pixels per inch. That's a big jump up from the HD 8.9's 1,920 x 1,200 display, not to mention the new HDX 7-inch tablet, which has a 1,920 x 1,200 screen. It's even enough to make the iPad Air's 2,048 x 1,536 resolution (264 ppi) seem modest. It's simply a gorgeous thing to behold, making movie watching a downright pleasure. Heck, it even managed to make Sharknado look pretty good, which is no small feat. All in all, images are sharp, the level of detail is impressive and the colors are vibrant."
    - Engadget

    But, I do agree with you that too many let their personal opinions colour their reading of reviews. I prefer Android and PC, but I have an iPad and have tried several Macs. Even though I prefer other units, there is no point in denying the excellent quality and style Apple products come with. They, like Nintendo, only release products "when they are done" - no rushing.
    Reply
  • MassiveTurboLag - Tuesday, October 29, 2013 - link

    Really? You clearly never looked over one of their Android phone reviews. They are stupidly detailed. 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
  • Solon - Wednesday, October 30, 2013 - link

    Wireless charging - deeply inefficient charging; maybe 50% of energy is actually picked up by the device
    Fingerprint scanner - probably getting one next gen
    Thunderbolt sync or USB3 - maybe; and it is possible the hardware already can do this; but Thunderbolt (a PCI-E spec) will never happen
    Haptic feedback - dead concept; no one actually wants this; RIM failed at haptic
    NFS - in a tablet? and is NFC actually used? No, it isn't.
    Reply
  • dishayu - Wednesday, October 30, 2013 - link

    Agree with your wireless charging argument, but that limits you from charging your iDevice if you don't have your own cable. All android phones use microusb, so it's not hard to find one at all (speaking of the real world here). Apple chose not to afford themselves that luxury.

    Fingerprint scanner : Although I think it's a gimmick and useless for the masses (almost everyone except from corporate users), they could have done it now, since they already have it in 5s. Why wait till next gen?

    Haptic feedback : You probably would have said the same about touchscreens around 2005. I tried staying away from smartphones altogether until the Xperia Pro because there were no decent phone with a proper keyboard. After that I finally gave in an bought the HTC One and I still really miss my physical buttons. Haptic feedback could cure that.

    NFC : I use it as much as I use Bluetooth (which is to say not a whole lot but a very handy feature still and I'd like to have it)
    Reply
  • ws3 - Tuesday, October 29, 2013 - link

    Yeah. Anyone who wanted to be truly objective would stopping running all of those tests that the iPad Air does so well in. If you want to be truly balanced, you have to run a bunch of tests that the iPad sucks at too, like maybe an .apk loading test or a malware running test. Reply
  • zeagus - Wednesday, October 30, 2013 - link

    +lulz Reply
  • KoolAidMan1 - Wednesday, October 30, 2013 - link

    Perfect Reply
  • pdjblum - Thursday, October 31, 2013 - link

    Anand himself has stated where his loyalties lie: He said during a podcast that his advertisers were the motivating force behind the change in the look of the website. Obviously he is a slave to his advertisers who obviously want as much crApple content on the site as possible; of course they want it be overwhelmingly positive. This crApple model generates tons of hits for theverge and it does the same for anandtech. Reply
  • markthema3 - Monday, November 4, 2013 - link

    He changed the layout of the site to better place the advertisments on the page. That's not catering to an individual company. The conclusion that he is therefore a slave to the advertisers is unfounded. Reply

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