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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  • michal1980 - Wednesday, October 30, 2013 - link

    Did you read? I was talking about windows 8.1, you know the big upgrade given away 2 weeks ago

    I know that in iSheep land windows doesn't exist.
    Reply
  • abazigal - Saturday, November 2, 2013 - link

    He's probably writing it even as we speak, and it will likely be posted in a matter a time.

    Anand has a ton of devices to review, so they have to set a priority. Not to mention that he has pretty much stated that he works on an iMac, so I imagine using Win8 actually takes away from his productivity time.
    Reply
  • algalli - Wednesday, October 30, 2013 - link

    Your right Windows 8.1 will be used by tens of people not hundreds of millions of people, at least in the tablet world Reply
  • jecastejon - Wednesday, October 30, 2013 - link

    And by the same standard, objectiveness and evidences you present I say you are paid by Apples's competitors. Reply
  • darwiniandude - Wednesday, October 30, 2013 - link

    Really?? Strange... The detailed review I just read complained (politely) about Apple not letting them dissect (cut open) review (loan) units. It also mentioned GUI performance frame rate drops in the multitasking UI and complained that due to 64bit they really need to ship with 2GB ram rather than the 1GB they come with. I can guarantee most other reviews out there will not mention these particular technical negatives. Anandtech reviews are thorough. Reply
  • Rickschwar - Thursday, October 31, 2013 - link

    Although I haven't seen too much Apple bias from AnandTech in the past, this is one of the most biased reviews I have ever read. This is surprising because normally AnandTech is the “gold standard” for all things technical. The reviewer talks about the iPad Air like it’s a revolutionary product, when there is little new about it. Apple was playing catch up in many ways and other tablets have many advantages over it. For example, the iPad 4 was thicker than many Android tablets. In fact, at least ten Android tablets were thinner than the iPad 4. The Air is only 1.9 mm thinner than the iPad 4 and tablets like the older Sony Experia Z are still significantly thinner than the iPad Air is (7.5mm vs. 6.9mm). Of course this wasn't mentioned in the article. Even when it comes to weight, the iPad Air isn’t dramatically lighter than the Experia Z (469g vs. 495g). That’s not mentioned in the article either.

    Since I’m in the market for a new tablet and I’ve owned two iPads in the past, I was hoping for big things with the new iPad, but for me and others it was a “meh” release. The same old display, the same A7 processor, and little real innovation. CNET agrees saying “Functionally, the iPad Air is nearly identical to last year’s model, offering only faster performance and better video chatting.”

    The most ironic part for my is the fact than more 90% of this article is based on benchmarks -- even though AnandTech has made it clear how easy it is to game benchmarks and others (including an article I wrote over a year ago published at Mostly-tech.com) have made compelling cases that benchmarks do not predict real world performance. This article mostly ignores real world performance and pretends that Android tablets don’t exist.

    After this article I will never look at AnandTech the same again. At least the CNET and Engadget reviews covered some of the limitations of this product.

    - Rick
    Reply
  • abazigal - Saturday, November 2, 2013 - link

    The ironic thing about your statement is that for the moment at least, only Android OEMs have been found guilty of gaming benchmarks, not Apple. So doing any benchmark tests at this juncture would actually favour Apple's competitors, despite this being a review of an Apple product. So I don't see what reason you have to complain, when the odds are stacked in Android's favour anyways.

    Besides, Anand has thoroughly dissected the A7 chip in his 5s review, and concluded that it is actually faster and more power-efficient compared to the higher-clocked, quad-core processors found in Android phones and tablets. The fact remains that Android and most mobile apps generally aren't optimised with 4-cores in mind either. So for all intents and purposes, Android tablets may as well not exist, since they will likely lose to the iPad in terms of real-world performance anyways.

    Also, the thing with these products is that they are ultimately a package deal. People don't just look at 1 single defining factor and buy a device based solely on that. Likewise, I am definitely not going to blindly buy the thinnest tablet in the market without first considering other factors like specs and availability of apps. You are not going to find that mythical Android tablet which is thinner, lighter, has a longer battery life, better screen, while boasting a larger market of apps and content.

    I am sorry, but you are not going to find a more objective and detailed review anywhere else. You want the iPad air to be bashed, go hand out at some pro-android forum instead.
    Reply
  • ADGrant - Saturday, November 2, 2013 - link

    "Same old A7 processor". You look like a complete idiot when you post something like that. The A7 was announced less than a month ago. Reply
  • sunflowerfly - Thursday, October 31, 2013 - link

    Anand biased? I do not believe that. They have no trouble pointing out Apple's flaws, and every product has them, nothing is perfect. The best products should win, and right now that happens to be Apple a lot of the time. Reply
  • ssiu - Tuesday, October 29, 2013 - link

    No 2GB RAM; hope dashed :(

    Does that mean an iPad 4 (which can only run 32-bit code) will end up "less RAM starved" than iPad Air running 64-bit code?
    Reply

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