The Display

The most visible improvement of the new iPad is naturally its Retina Display. Originally introduced with the iPhone 4, the concept of an Apple Retina Display was created to refer to a display where the pixel density was high enough that the human eye, at a standard viewing distance, could not resolve or identify individual pixels.

Unlike traditional OSes, iOS doesn't support a laundry list of display resolutions. The iPhone was introduced at 480 x 320 (3:2 aspect ratio), while the iPad came to be at 1024 x 768 (4:3 aspect ratio). Rather than require iPhone applications be redesigned for a higher resolution iPhone, Apple simply doubled both the vertical and horizontal resolution for the iPhone 4—maintaining the same aspect ratio as the previous models, and only requiring higher quality assets, not a redesigned UI, to take advantage of the new display.

The iPad on the other hand always required a redesigned UI to make the most of the iPad's larger display and higher resolution. With a different aspect ratio, simply scaling up an iPhone app wouldn't work (although to enable backwards compatibility Apple did allow you to do just that). Admittedly Apple wouldn't want to allow such easy portability between iPhone and iPad apps as it wanted the extra effort to improve the quality of tablet apps.

The new iPad does what the iPhone 4 did and doubles both horizontal and vertical resolution: from 1024 x 768 to 2048 x 1536. All iPad applications work by default as developers don't directly address pixels but rather coordinates on the screen. Existing apps take up the full screen, and if higher resolution images are present they are used as they avoid the interpolation associated with scaling up an image designed for the original iPad resolution. For example, below we have a makeshift iOS icon in three different forms—10x7 native (72x72), upscaled to a 2x version using bicubic interpolation (144x144), and a 2x resolution version (144x144):

72x72
144x144 (Upscaled)
144x144 (Native)

The upscaled form looks good, but the 2x resolution version looks better.

More traditional OSes have always given you additional desktop real estate with increased resolutions. iOS simply gives you a better looking desktop. This distinction is arguably one of the reasons why the new iPad's display can be so polarizing. As consumers of high-end displays we're used to higher resolution going hand in hand with a larger panel size. Alternatively, we're used to a higher resolution enabling us to see more on a screen at one time. In the case of the new iPad, the higher resolution just makes things look sharper. It's a ton of work for an admittedly more understated impact, but it's the type of thing that simply had to be done.

Retina Display Enabled Apps

Apple has created such a healthy marketplace with the app store that developers are eager to quickly deliver apps with updated graphics for the new iPad. Sure enough, by the day of launch we saw several high profile applications with higher resolution assets for the new iPad. The motivation to have Retina Display support is huge as Apple is actively promoting those apps that have been updated for the new iPad via the app store:

These updated apps now come with larger image assets, which can increase the total app size. Not all apps will grow in size (e.g. Infinity Blade 2 simply renders at a higher resolution vs. using tons of new content, not to mention that textures are already heavily compressed) but some have/will. The retina burden unfortunately impacts all iPads as there's only a single app package delivered upon download. Even if you don't use them, the higher resolution retina graphics are there.

Note that iPhone apps will now load their Retina assets (designed for 640 x 960) rather than their normal assets (designed for 320 x 480) on the new iPad, resulting in a significant improvement in image quality there as well:

Games are a special exception to the 2x asset scaling of the new iPad. Applications that simply have their UI accelerated by the A5X's GPU do fairly well at the iPad's native resolution. 3D games are another story however.

If all you're doing is determining the color of a single pixel on the screen, not impacted by lights in 3D space or other transparent surfaces above the surface, it's a relatively simple and painless process. For the majority of what you're looking at in iOS, this is simply the procedure. The app instructs the drawing APIs to place a red pixel at a set of coordinates and that's what happens. In a 3D game however, arriving at the color value of that pixel can require quite a bit of math, and quite a bit of memory bandwidth.

Game developers have a few options on the new iPad. One option is to not update a game, running it at 1024 x 768 and rely on the iPad's scaler to upscale the image to 2048 x 1536. The game will take up the full screen, run faster than on the iPad 2, but it won't necessarily look any better. Low resolution content upscaled to a higher resolution display still maintains much of the aliasing you'd see at a lower resolution.

Another option is to render all scenes at the new iPad's resolution: 2048 x 1536. With four times the number of pixels to fill and only 2x the compute and memory bandwidth compared to the iPad 2, this will only work for fairly lightweight content. Not to say that it's impossible—even GLBenchmark's Egypt test, in its current form, actually runs very well at the new iPad's native resolution. Many stressful 3D games won't fall into this category however.

The third, and more popular option is for a game developer to render all frames offscreen at an intermediate resolution between 1024 x 768 and 2048 x 1536, then scale up to the panel's native res. So long as the developer maintains aspect ratio, it'll be possible to use this approach and get a good balance of higher resolution and performance.


Infinity Blade 2 for the new iPad Renders at roughly 1.4x the iPad 2's resolution, then upscales to fill the screen

Infinity Blade 2, for example, renders offscreen at roughly 1.4x the resolution of the iPad 2 before scaling up to 2048 x 1536 for final display. The result is a sharper image than what you'd get on an iPad 2, without sacrificing performance.

Game developers may choose to increase the level of anti-aliasing instead of or in combination with an increase in resolution. As we'll discuss shortly, Apple's A5X does come equipped with more GPU execution resources and dedicated memory bandwidth for graphics that would allow for an increase in quality without a corresponding decrease in frame rate.

The new iPad The Display: In Numbers
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  • doobydoo - Saturday, March 31, 2012 - link

    Lucian Armasu, you talk the most complete nonsense of anyone I've ever seen on here.

    The performance is not worse, by any stretch of the imagination, and lets remember that the iPad 2 runs rings around the Android competition graphically anyway. If you want to run the same game at the same resolution, which wont look worse, at all (it would look exactly the same) it will run at 2x the FPS or more (up-scaled). Alternatively, for games for which it is beneficial, you can quadruple the quality and still run the game at perfectly acceptable FPS, since the game will be specifically designed to run on that device. Attempting anything like that quality on any other tablet is not only impossible by virtue of their inferior screens, they don't have the necessary GPU either.

    In other words, you EITHER have a massive improvement in quality, or a massive improvement in performance, over a device (iPad 2) which was still the fastest performing GPU tablet even a year after it came out. The game developers get to make this decision - so they just got 2 great new options on a clearly much more powerful device. To describe that as not worth an upgrade is quite frankly ludicrous, you have zero credibility from here on in.
    Reply
  • thejoelhansen - Wednesday, March 28, 2012 - link

    Hey Anand,

    First of all - thank you so much for the quality reviews and benchmarks. You've helped me build a number of servers and gaming rigs. :)

    Secondly, I'm not sure I know what you mean when you state that "Prioritizing GPU performance over a CPU upgrade is nothing new for Apple..." (Page 11).

    The only time I can remember Apple doing so is when keeping the 13" Macbook/ MBPs on C2Ds w/ Nvidia until eventually relying on Intel's (still) anemic "HD" graphics... Is that what you're referring to?

    I seem to remember Apple constantly ignoring the GPU in favor of CPU upgrades, other than that one scenario... Could be mistaken. ;)

    And again - thanks for the great reviews! :)
    Reply
  • AnnonymousCoward - Wednesday, March 28, 2012 - link

    "Retina Display" is a stupid name. Retinas sense light, which the display doesn't do. Reply
  • xype - Thursday, March 29, 2012 - link

    GeForce is a stupid name, as the video cards don’t have anything to do with influencing the gravitational acceleration of an object or anything close to that.

    Retina Display sounds fancy and is lightyears ahead of "QXGA IPS TFT Panel" when talking about it. :P
    Reply
  • Sabresiberian - Thursday, March 29, 2012 - link

    While I agree that "Retina Display" is a cool enough sounding name, and that's pretty much all you need for a product, unless it's totally misleading, it's not an original use of the phrase. The term has been used in various science fiction stories and tends to mean a display device that projects an image directly onto the retina.

    I always thought of "GeForce" as being an artist's licensed reference to the cards being a Force in Graphics, so the name had a certain logic behind it.

    ;)
    Reply
  • seapeople - Tuesday, April 3, 2012 - link

    Wait, so "Retina Display" gets you in a tizzy but "GeForce" makes perfect sense to you? You must have interesting interactions in everyday life. Reply
  • ThreeDee912 - Thursday, March 29, 2012 - link

    It's basically the same concept with Gorilla Glass or UltraSharp displays. It obviously doesn't mean that Corning makes glass out of gorillas, or that Dell will cut your eyes out and put them on display. It's just a marketing name. Reply
  • SR81 - Saturday, March 31, 2012 - link

    Funny I always believed the "Ge" was short for geometry. Whatever the case you can blame the name on the fans who came up with it. Reply
  • tipoo - Thursday, March 29, 2012 - link

    iPad is a stupid name. Pads collect blood from...Well, never mind. But since when are names always literal? Reply
  • doobydoo - Saturday, March 31, 2012 - link

    What would you call a display which had been optimised for use by retinas?

    Retina display.

    They aren't saying the display IS a retina, they are saying it is designed with retinas in mind.

    The scientific point is very clear and as such I don't think the name is misleading at all. The point is the device has sufficient PPI at typical viewing distance that a person with typical eyesight wont be able to discern the individual pixels.

    As it happens, strictly speaking, the retina itself is capable of discerning more pixels at typical viewing distance than the PPI of the new iPad, but the other elements of the human eye introduce loss in the quality of the image which is then ultimately sent on to the brain. While scientifically this is a distinction, to end consumers it is a distinction without a difference, so the name makes sense in my opinion.
    Reply

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