The Apple iPad Review (2012)by Vivek Gowri & Anand Lal Shimpi on March 28, 2012 3:14 PM EST
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):
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.
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Steelbom - Thursday, March 29, 2012 - linkI'm curious why we didn't see any graphics benchmarks from the UDK like with the iPhone 4S review?
Craig234 - Thursday, March 29, 2012 - linkWow, this is good to buy... 'if you are in desperate need for a tablet'?
That's a pretty weak recommendation, I expected a much stronger endorsement based on the review.
Chaki Shante - Friday, March 30, 2012 - linkGreat, thorough review, thanks Anand et al.
Given the sheer size of the SoC (like 4x larger then Tegra2 or OMAP4430, and 2x Tegra3), you'd bet Apple has the fastest current SoC, at least GPU-wise.
This SoC is just huge and Apple's margin is certainly lowered. Is this sustainable on the long run ?
I wonder if any other silicon manufacturer could make same size devices (not technologically but from a price perspective) and expect to sell them.
dagamer34 - Friday, March 30, 2012 - linkNo one else needs to crank out so many chips that are the same. Also, other companies will be waiting long enough to use 28nm, so there's little chance they'll be hitting the same size as the A5X on 45nm.
Aenean144 - Friday, March 30, 2012 - linkSince Apple is both the chip designer/licensee and hardware vendor, it saves them the cost of paying a middleman. Ie, Nvidia has to make a profit on a Tegra sale, Apple does not, and can afford a more expensive chip from the fab compared to the business component chain from Asus to Nvidia to GF/TSMC and other IP licensees.
I bet there is at least 50% margin somewhere in the transaction chain from Asus to Nvidia to GF/TSMC. Apple may also have a sweetheart IP deal from both ARMH and IMGTEC that competitors may not have.
shompa - Friday, March 30, 2012 - link@Aenean144
Tegra2 cost 25 dollars for OEMs and 15 dollars to manufacture. A5 cost Apple 25 dollars to manufacture. By designing its own SoC Apple got 30% larger SoC at the same price as Android OEMs.
Tegra3 is huge. That is a problem for Nvidia. It costs at least 50% more to manufacture. Nvidia is rumored to charge 50 dollar for the SoC.
A5X is 50%+ larger then Tegra3. Depending of yields it cost Apple 35-50 dollar per SoC.
The integrated model gives Apple cheaper SoCs, but also custom designed for their needs. Apple have a long history of Accelerating stuff in its OS. Back in 2002 it was AltiVec. Encoding a DVD on a 667mhz powerbook took 90 minutes. The fastest X86 AMD 1.5ghz it took 15 hours. (and it was almost impossible to have XP not bluescreen for 15 hours under full load). Since 2002 Apple accelerate OSX with Quarz Extreme. Both these techniques are now used in iOS with SIMD acceleration and GPU acceleration. Its much more elegant then the brute force X86 approach. Integrated makes it possible to use slower, cheaper and more efficient designs.
shompa - Friday, March 30, 2012 - linkThe A5X SoC is a disaster. Its a desperation SoC that had to be implemented when TSMC 28nm process slipped almost 2 years. That is the reason why Apple did not tape out a 32nm A5X on Samsung. PA Semi had to crank out a new tapeout fast with existing assets. So they took the A5 and added 2 more graphics core.
The real A6 SoC is probably ready since long back, but TSMC cant deliver enough wafers. The rumored tapeout for A6 was mid 2011. Apple got test wafers from TSMC in june and another batch of test wafers in october. Still at this point Apple believed they would use TSMC for Ipad3.
ARM is about small, cheap and low power SoCs. That is the future of computing. The A5X is larger then many X86 chips. Technically Intel manufactures many of its CPUs cheaper then Apple manufactures the A5X SoC. That is insane.
stimudent - Friday, March 30, 2012 - linkProducts reviews are fun to look at, but where there's a bright side, there is always a dark side. Maybe product scoring should also reflect how a manufacturer treats its employees.
name99 - Friday, March 30, 2012 - linkYou mean offers them a better wage than they could find in the rest of China, and living conditions substantially superior to anywhere else they could work?
Yes, by all means let's use that scoring.
Or perhaps you'd like to continue to live your Mike Daisey dystopia because god-forbid that the world doesn't conform to your expectations?
Craig234 - Friday, March 30, 2012 - linkI'm all for including 'how a company treats its employees' and other social issues; but I'd list them separately, not put them in a product rating.