The Complete iPad 3 Review: Retina Display, A5X, 4G LTE, And Camera

Driving Higher Resolutions Requires More Power

The iPad 3's display is visually stunning. But driving more pixels using a more powerful graphics processor requires a trade-off in the form of higher power use. (If you're not familiar with the A5X or how it compares to other SoCs, read our earlier part one coverage of the iPad 3.)

Rather than using a larger panel, which would have been impractical on a tablet, Apple's Retina display occupies the same 9.7" footprint, augmenting resolution through greater pixel density. The result, however, is increased power consumption that tracks in much the same way you'd expect from 22" and 27" screens running at different resolutions. In that parallel, the 27" monitor consumes 3x to 4x more energy as it drives more pixels. Apple is unable to mitigate the increased power consumption normally associated with higher-resolution screens because it's still using panels manufactured with amorphous silicon. These displays are far less energy efficient than the Low Temperature Poly Silicon (LTPS) used on the iPhone's Retina display.

Desktop Power Consumption
Core i5-2500K, HD Graphics 3000 System
1280x720
1920x1080
Desktop Idle
49.1 W
50 W
Call of Duty: Modern Warfare 3
101 W
104 W


The iPad 3's high-resolution display also requires a more powerful graphics processor, which had its own impact on power use. More pixels on the screen necessitate a faster piece of silicon to draw and render, just to maintain similar performance. Although desktop PCs feature much more thermal flexibility, the chart above illustrates our point: a GPU has to work harder at higher resolutions, reflected in a power measurement. This is just as applicable on a tablet employing embedded graphics.

Fortunately, the iPad 3 features Apple's new A5X SoC. It's fundamentally the same as the iPad 2's A5, except that it has four GPU cores, effectively doubling graphics potential. The A5X powers the iPad 3's display at 2048x1536 just as smoothly as the A5 at 1024x768.

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    Top Comments
  • aicom
    Tomfreaklol FAIL hard when I see keyboard are displayed on TV as well despite being docked and to make thigns worst one still need to carry the adapter around to plug HDMI......

    +1 to the keyboard thing. But remember that most tablets (all?) don't have full size HDMI so you probably need a dongle 99% of the time anyway.
    13
  • alchemy69
    "Typically, you're looking at a tablet from less than a foot away"

    Really?
    11
  • confish21
    its cool if I lick my finger for page turning right?
    11
  • Other Comments
  • tomfreak
    lol FAIL hard when I see keyboard are displayed on TV as well despite being docked and to make thigns worst one still need to carry the adapter around to plug HDMI......
    -6
  • confish21
    Really a solid tablet. Just wish the adapter and outrageous bills could disappear... Great Review!

    100 degrees is damn hot but I think the results are justified.
    4
  • confish21
    its cool if I lick my finger for page turning right?
    11
  • hardcore_gamer
    I'm waiting for an x86- Windows 8 tablet.
    6
  • aicom
    Tomfreaklol FAIL hard when I see keyboard are displayed on TV as well despite being docked and to make thigns worst one still need to carry the adapter around to plug HDMI......

    +1 to the keyboard thing. But remember that most tablets (all?) don't have full size HDMI so you probably need a dongle 99% of the time anyway.
    13
  • tomfreak
    HDMI port is not very thick, I still wonder whats keeping them from putting in on tablet.
    2
  • Maziar
    Great article! very detailed.
    -1
  • aicom
    TomfreakHDMI port is not very thick, I still wonder whats keeping them from putting in on tablet.

    The port isn't all that's needed. There's also a bit of hardware around it for the socket that makes it a tad thicker and a stretch to fit in the chasis of tablets.
    1
  • alchemy69
    "Typically, you're looking at a tablet from less than a foot away"

    Really?
    11
  • tomfreak
    aicomThe port isn't all that's needed. There's also a bit of hardware around it for the socket that makes it a tad thicker and a stretch to fit in the chasis of tablets.
    looks like we gonna wait wide adoption for mini display port for TV then.
    2
  • bustapr
    more than 5hrs to charge. thats not to my liking. the transformer prime was the only battery life vs charge time tablet I saw.
    3
  • Augray37
    The display is 9.7", not 10.1".
    1
  • cknobman
    Alchemy69"Typically, you're looking at a tablet from less than a foot away"Really?


    Yeah I thought that comment was bunk too. Typically I use my tablet 1-2 feet away as less that 1 foot away would have the thing shoved up in my face too much and not give me any arm reach to operate the device properly.

    As for the display in the iPad3 I went to the apple store and looked at it side by side with the iPad2. The colors look great but the super high pixel density was not as big of a difference as these reviews made it out to be.

    The biggest things I noticed when comparing iPad2 and 3 side by side was the increased thickness and weight. Those 2 factors were enough for me to want to choose the iPad2, especially if I could get it a little cheaper than the iPad 3.
    3
  • mcd023
    I am curious, was it just a reduction in pixel size that made the higher gamut? that doesn't really make sense to me. Does anyone have more info?
    1
  • nycnut
    The data plan graphic is WRONG! Verizon offers 2GB vs ATTs 3GB for the same $30. Check your facts...
    -3
  • hoofhearted
    I am not a fanboy of either camp. I have a tf prime and just got the ipad 3. I just wish apple would put a friggin sd slot. Watching my dvd collection while at the gym on the eliptical machine is a must and I am not fond of jumping though hoops to swap content in and out.

    I also am curious about who will get the gaming win (more depends on where the devs go):
    android tegra3, ipad3, vita, 3ds, or maybe microsoft will pull a rabbit out of their hat with win8.
    1
  • badtaylorx
    damn....i dont come here for apple news.....
    -5
  • jamesjones_det
    I'm not supporting and/or dissing the iPad or Tom's hardware but technically there is a "wireless" option with AirPlay and an Apple TV or Mac.

    I'm just saying if we are supposed to be a technology site we should be sure the facts are correct.
    0
  • CaedenV
    give me a 16:9 or 16:10 tablet capable running an independant 1080 or 1200 capable external display with a native miniHDMI connector for easy setup for presentations and video watching (does not need 3D support on external display). I also want removable storage for SD cards as an option, and a USB port or 2 if it is not too much to ask so I can hook up my video camera, or keyboard, or credit card swiper without dealing with a dock. Lastly, I want a minimum 128GB of internal storage on it for $300-400. I will take a slower processor, or lowered graphics for the sake of a minimum 128GB of storage. Lastly, I want full MS office to run on it, none of this web-based office365 junk, especially if I am going to be out and about and not wanting to waste my 4G plan just to run office.

    If I am going to pay $830 for a limited use tablet with 64GB storage and 4G, then I think I would rather spend that money on a notebook or ultrabook. I can still get a touch screen, I still get good graphics, I get a real keyboard/mouse, can still get a 4G option, and I get real x86 programs, removable storage, better connectivity options (USB3, thunderbolt), and (most importantly) real storage space.

    Also, I would prefer win8 over iOS, but iOS is not a deal breaker if they would come out with something that would fit my use.
    1
  • acku
    nycnutThe data plan graphic is WRONG! Verizon offers 2GB vs ATTs 3GB for the same $30. Check your facts...

    My fault. Corrected.

    Cheers,
    Andrew Ku
    3