Battery Life

With the move from featurephones to smartphones, battery life has been and continues to be a critical issue. While it wasn’t unusual to see a week or more of battery life on a featurephone, some of the earliest smartphones couldn’t even last a day. While tablets seem to have a much easier time achieving high levels of battery life by virtue of massively increased volume, they still face similar issues as they are often used for gaming or other more intensive workloads that a smartphone is unlikely to see nearly as often. In order to test this, we run our tablets through a standard suite of tests of various use cases. In all cases where the display is on, all displays are calibrated to a brightness of 200 nits to draw useful relative comparisons.

Web Browsing Battery Life (WiFi)

In our first test, we see that the iPad Air 2 is about roughly equivalent to the original iPad Air for WiFi web browsing. This is actually a bit surprising as the battery in the iPad Air 2 is approximately 84% of the iPad Air. This would mean that we would expect the iPad Air 2 to get around 8.4 hours of battery life in this test, which represents a 16% gain to efficiency. It’s likely that these improvements to battery life come from the new process node on the A8X, along with the newer WiFi module.

Web Browsing Battery Life (4G LTE)

Along the same lines, the LTE web browsing test tracks quite closely but it seems that there’s a minor decrease in efficiency gains when compared to WiFi. This difference is likely to be explained by the much higher bandwidth available in WiFi when compared to LTE.

While the web browsing tests are effective at ensuring faster SoCs aren’t punished, this inherently tilts battery life towards a more display-bound mode rather than compute-bound. Unfortunately short of a jailbreak it doesn’t seem possible to get an effective Basemark OS II battery test, so we’re mostly limited to a test of GFXBench’s unlimited rundown.

GFXBench 3.0 Battery Life

GFXBench 3.0 Performance Degradation

As one can see, the iPad Air 2 is one of the best performers on this test, considering its frame rate and runtime. While NVIDIA's GK20A GPU in Tegra K1 can get close to the GX6650 for short periods of time, over a long workload it's pretty clear that the GX6650 on 20nm has better sustained performance and significantly superior efficiency as it doesn't throttle until the 200th iteration of the test. It's important to note that the iPad Air 2 is running at a higher native resolution here, so relative to SHIELD Tablet a scaling factor needs to be estimated in order to get an idea for performance at the same resolution. During this test I saw that the skin temperatures never exceeded 45C, so this isn't the result of Apple choosing to run the device hotter than most.

Charge Time

While tablets deliver some great battery life in general, charge time tends to be much slower than that of smartphones as the battery is much larger and charging the device isn't as time critical due to the longer battery life . While we can't quite cover the full range of battery life uses cases, it's important to remember that in cases where the platform is otherwise identical beyond display that battery life scales linearly with overall capacity. In order to test charge time, we measure the time it takes for the battery to reach 100% from a fully-depleted state.

Charge Time

As one can see, the smaller battery seems to have a noticeable impact on charge time, although the difference isn't really all that notable as the difference is only around ten minutes at the end of the day.

GPU and NAND Performance Software: iOS 8
Comments Locked


View All Comments

  • JRX16 - Wednesday, January 7, 2015 - link

    Yeah, that happened once and will likely never ever happen again... nice cherry pick there.
  • drunkbananas - Friday, November 7, 2014 - link

    I thought native audio/video file transfer were still restricted to iTunes. Can I put music and Blu-Ray rips on an iOS device and open them with more than one audio/video player?

    What about apps that used to require iTunes to load data in them, can I now just use regular USB?
  • Samus - Friday, November 7, 2014 - link

    I've had an iPhone 4S for over a year, my first Apple product...and it replaced my technically superior but buggy as hell Galaxy S3.

    Still haven't installed iTunes and I've upgraded from IOS 6 through IOS 7 and IOS 8.

    I *almost* installed iTunes to downgrade back to IOS 7 while Apple was still permitting it, but I got used to the...lets just say, lack of smoothness my phone once had.

    I had an HTC Dream (G1) years ago so I'm accustomed to jerky UI's by now.

    The reason I like the iPhone comes down to the app store, the camera, battery life and size. It's really hard to find a <4" phone anymore and the GS3 was just too big for me.
  • blacks329 - Saturday, November 8, 2014 - link

    Google Music Play All Access or whatever mouth full of words its called works fine for audio. I've been wifi transferring video files from any computer on the same network to the VLC app on my iOS device for a couple of years now and haven't had a problem.

    No USBing it over to the device however, but most things use either a cloud back end or wifi transferring for files. I've never had to plug my iPhone or iPad into a computer except to charge it for years now.
  • carloshehe - Sunday, November 9, 2014 - link

    That requires a WiFi set up that people may not have or understand how to do it.

    Its just called Play Music.
  • akdj - Thursday, November 27, 2014 - link

    Play music. Play video. Play magazines. Play books, tones, podcasts, an app tray in alphabetical order, Google Ringtones? (I'm a Note 4 & iPhone owner and enjoy both, honestly!). Your TV shows? Actual app 'layout' on a far superior and quicker rig is quite useful if you're interested in changing your UI. Wifi, no need. NFC is here now and Airdrop destroy NFC when it comes to transferring files from computer to phone, tab or vice versa. No need for a separate wifi zone
    No LTE or data charges apply.
    It seems as though about a ½ billion people understand it, I'm not sure who you're talkng to that doesn't get it. One of the overlooked and most desirable ios feature and strength is it's optimization of hard and software, lack of carrier bloat and the MOST active development community in history. The cool thing, when compared to its counterpart is this Eco system isn't limited to a certain, average sized phone
    Developers take the time to optimize the app for larger dispalys...including the tablet form factor unlike Android (5.0 from the Nexus reviews I've seen)
    As a business owner if 27 years, husband, father and pilot... iOS has literally revolutionized our business's in the past five years
    Mini 2 is my kneeboard, flight planner, fuel calculator, Jep charts and up to date plates, real time weather and traffic, the flight manual for each plane, and it's shaved off 47 of the 48 pounds my flight bag was consistently consuming. One of my son's grades have come up from C+/B- to all As! Due solely to the's learning software and compelling nature and new idea of 'learning'. A tutor for the year wouldn't have improved his grades as much and would've doubled the price
    The iPhone 6+ is hand's down the best iPhone to date. I'm not familiar with the 6, as we've been using Notes and the earlier 3.5" & 4" iPhones. It's balance and weight, slim form factor and incredible speed is unparalleled Note 4 screams and looks great. I'm using adaptive screen for adjustments to the saturation but for me, it's the tool we need on site as we produce audio, video and still shots from all over Alaska. We've been lucky enough to work with Nat Geo, Smithsonian and Discovery (several of their subs) and in Alaska, without a plane you're not going to get 99% of her.
    We also provide mobile production and have hosted many hundreds of parties over the past three decades in villages from St George and Paul NW AK and Montague where you CAN see, not Just See Russia, but ice fish if you're crazy enough on their territory. Cool thing ...our snow machines (Alaskan for snowmobile;)) --- to Juneau, Ketchikan, Wrangle, Hoonah, Eek in the southeast. & up and down the Aleutian chain
    None of this would be possible without today's technology. From the Beechcraft and Otter's nav aids and instrumentation for inclement weather to setting a three song ceremony up outdoors and amplifying the official! Ten years ago, burn a CD with the processional, bride's march and recessional we were humping a couple hundred pounds for that fifteen minutes of ceremony
    Today, an iPad, three lavaliere mics and the 45 pound, suitcase Fender 500 ...three minutes TJ break down, maybe ten to put together and we're able to double our bookings as the bigger rigs can now solely be used for the reception ....again, whether 'Play Music' or iTunes on a phone or tablet is an incredible backup to have on hand in these situations --- computer goes down, you're instant on. dJay2, Pinnacle and I can't start the list of incredible DAWS we routineky work with make editing and playlist building a breeze. dJay with a controller is flat amazing as is Traktor, vJay, and the ability to wirelessly control AirPlay to projectors and the GoPro cams with music video mix has landed contracts for our business at five of the seven local high schools and a dozen junior highs. And it's a HELLUVA lot cheaper than buying a smart, moving head, laser system (we've got a both, and plenty of LED ParCans, effects, etc....but video is another level of 'cool' to the younger generation...
    ....Which I think leads me to my point. To those of you 20 something's that grew up connected, with a cell phone and computer...DON'T limit yourself. The Note4 &. Stylus allow me to sketch with structural engineers rigging positions, sign their credit cards with a 'pen' instead of a finger and they're incredibky fast. Wicked fast and a night and day difference between N1&2
    That said, limitarions imposed by Google on 'external' (internal microSD) storage is a JOKE! Always makes me laugh when the Android camp points Apple's pricing on NAND as a 'ripoff' ...IMHO, a ripoff or bargain as I see it, no matter how YOU see it, the 'option' is there. My 'flagship' Noten4 comes in a single size. 32GB, about a third of which isn't available due to the OS
    Then, there's a very arbitrary system of which apps can and can't be moved to the card. Bizarre and getting worse. Note 3 I had if I moved the app, it moved the WHOLE app.
    Now, with 4.4 I'm able to move 'some' third party apps, no AT&T or Samsung bloat to the microSD card. Slower NAND, less storage options and a terrible development community, for me...make the decision easy, especially with the new iOS releases; 6, 6+ and Air2 (WOW, this is another level of badass!)---a second and a ½ generation 64bit SoC, battery/efficiency monsters and mind blowing objective measurements
    And it doesn't end there. There's not a single solitary laptop on the market that can come close to the again, 2 ½ generation rMBP. The 15" I bought in 2012 changed comouting to me. HiDPI display is beyond awesome, the SSD speeds were phenomenal, power was incredible and at 4 pounds and seven hours of usage away from 110 was an absolute JOY!
    I just picked up the recently updated Haswell model witht the PCIe SSDs, the bigger 2GB 750 and Iris Pro (5200---& if you've yet to see the IP5200 in action, go to an Apple Store, Best Buy, wherever and play with it. Again, and as expected an iGPU from Intel that is unreal!
    MSI, Alienware, Clevo....9-12 pound 52 minute gamer monstrosities are a dying breed. Home built desktops for the enthusiast will stick for a while but when the power from a four pound laptop as a 15" 2014 rMBP demonstrates with a TB PCIe storage system, I'm reading and writing right at or just over a Gb/s! The new MP replaced (finally ,in March after waiting a bit) my 2010 octocore and runs circles around it! And I had put the 830s in for SSD, better GPU, didn't matter)
    What Apple's doing today in phones, tabs, lap & desktops is incredible and with iOS 8/OS X 10.10, you're immediately set up with a 'hot spot' for your laptop.
    Metal, elimanting the thick mud of OpenGL ES and allowing developers to work 'right on the metal'. No middle man. Shared cache for the memory so it can simultaneously be accessed but the CPU and GPU as well as continutiy, handoff....and SWIFT! They wrote an entirely new code from scratch, it's incredible and free to learn! Once you've played a bit, grab XCode for free and play around with building your own app, for your use.
    Don't limit yourself to a single choice. No company is worth that type of 'fandom'. It's not football (American or 'real' everywhere else in the world, AKA soccer). It's a phone. A computer. A tablet. Buy wait works for YOU. Not what some DBag online says, your peers are using or based on reviews from sites other than here, ARS....maybe a couple others.
    Once you buy, don't read the comments!
  • NEDM64 - Saturday, November 8, 2014 - link

    Yes, you can.

    Most App's you upload files via HTTP, FTP, almost all support AirDrop.

    What about USB syncing?

    Can you only sync a playlist with your android, that you update in your PC, and then auto-syncs the playlist, and the music?

    Can you sync your entire library (or some albums, or some playlist), but transcode your music to a specific bitrate?
  • carloshehe - Sunday, November 9, 2014 - link

    The only way to get music to play in your iPad without plugging it into anything is to use a cloud storage app that plays media.
  • nyastra - Sunday, November 9, 2014 - link

    1) Dropbox, OneDrive, GoogleDrive
    2) Yes - VLC,etc

    Spotify, Amazon
  • akdj - Thursday, November 27, 2014 - link

    No need for USB. We've got AirPlay. No need for iTunes for years. But it's still a killer piece of media management software and runs well, fluently and keeps your crap in a 'third' and physical location If you're looking to save pics, vids, drawings ...projects, whatever, sure there's a lighting to USB adaptor.
    I don't think I remember Ever having to use iTunes to 'load data on them' ...or are you talking about the early days of syncing music and media, etc?
    Regardless, no need. Myself...I orefer DropBox. It's in my finder, toolbar (both on 10.10 and 8.1) and iOS as well as Android. It's an amazing app with excellent reliability and a bill a year to ensure the safety of a TB of data is invaluable.
    Office 365 as well, ten bucks and five TBs Of storage, one formal, three kids, as well, my wife and I! Oh, comes with this word editor/text editor, a 'spread sheet' thingy and this pretty slick, not quite keynote wannabe;) --- no, I'm being sarcastic. Five tabs, five computers. XPlatform
    Just Incredible! $20/year per TB of storage.
    Unfortunately it's Windows and therefore not nearly as 'open' or able to be baked into OS X. SkyDrive kicks was on 8.1 though.

Log in

Don't have an account? Sign up now