Mark Trapp

A Retina display-equipped iPad? Don’t hold your breath

Author note

This blog post was written in early 2010, right after world got its first taste of cheap HiDPI displays in the form of iPhone 4. While HiDPI displays are common (if not ubiquitous) now, they were anything but in 2010. The historical significance of this post is that it took 2 years to see a HiDPI iPad (or, for that matter, consumer-grade HiDPI displays larger than 4 inches diagonal), not 6 months as was being predicted at the time.

Every minute, some technology analyst is predicting the future. 99 times out of 100, they're wrong. And it's not really worth writing about. But every once in a while, there's a prognostication that's so crazy—but nevertheless written as though it's an inevitability—it pains the mind.

Today, MG Siegler wrote an article about how iPad looks like old news compared to the forthcoming iPhone 4. In it, he opines that, among the main problems the just-released iPad has, its display simply doesn't measure up to the new iPhone 4's display. I take him at his word: I haven't seen it yet, and nearly everyone who has says it's an amazing display.

But he continues:

Here’s why this really matters for Apple: the iPhone 4 likely points to the updates coming to the iPad in the not-too-distant future. Are there any doubts that the Retina Display and twice the RAM will make its way to that device? So why would you buy the iPad now if the device might get these updates in say, January? The proof will be right in front of your eyes on Thursday.

Hot damn, don't buy an iPad! Or if you already have, you poor bastard you, sell it on eBay! In January, we're going to have a new iPad (I'm calling it the "iPad Unicorn") with a sick Retina display!

If you believe that, or if you can follow that logic, I'm going to save you some trouble now and tell you it's not going to happen.

The facts

Let's start with the knowns: the iPhone 4 has a 3.5" display with a resolution of 960×640 pixels. This gives it a pixel density of 326 ppi. The current iPad has a 9.7" display with a resolution of 1024×768. This gives it a pixel density of 132 ppi.

In order for Apple to equip the next-generation iPad Unicorn with a comparably dense display as the new iPhone 4, they'd have to up the pixel density by a factor of around 2.47. Given the same form factor, we're looking at a truly amazing 9.7" screen with a resolution of a staggering 2530×1897 pixels. Imagine the pornography you could watch with a screen like that.

Not so fast. Let's put aside pure flights of whimsy and magic that such a large display could be manufactured at all at this time (much less for an affordable price), consider a few comparative figures:

  • The new MacBook Pro I own currently sports a resolution of 1440×900.1
  • The 24" LED monitor Apple sells has a max resolution of 1920×1200.2
  • Even 1080p video, currently the upper threshold of video quality, clocks in at a relatively crummy 1920×1080.3
  • Finally, we find something that has a comparable (but still inferior) resolution at 2560×1440 pixels: the 27" iMac.

The reality

I list devices that are far larger for absurdity's sake, but the important figure is the resolution of 1080p video. Even under ideal conditions where battery, storage space, bandwidth, and processing power are non-factors the best video available to most consumers would look gross on the mythical iPad Unicorn.

But we don't live in an idealized world. There are too many factors, at this point in consumer technology, for such a feat of human largesse to be feasible. Firstly, Apple needs to have an infrastructure in place to deliver 1080p video on the iTunes store (and it can't be super compressed like the current 720p it calls HD; such crummy video would look awful on such a device).

Getting past that, the iPad Unicorn needs the processing power to decode a 1080p stream. While I have no doubt there will be advancements in decoding, consider the requirements to get 1080p video to decode in QuickTime. There are no chips in anyone's roadmap that come close.

Thirdly, the iPad Unicorn needs the battery life we have all come to expect from the current version. With its current battery, it's rated to get up to 10 hours watching video. That's with the battery taking up almost the entire chassis. Let's be generous and say the iPad Unicorn only takes an additional 25% more processing power. Again, there are no chips in anyone's roadmap that will perform 25% better but take the same amount of power. So we need a bigger battery. Where's it going to go in a product that has to fit within Apple's mantra of "thinner is better"?4

Finally, we need to talk about bandwidth and storage. Currently, a feature-length heavily-compressed 720p video on iTunes takes 3.95 GB of space.5 Forget about 3G downloads. Forget about 4G downloads. Heck, forget about most WiFi connections. The iPad Unicorn is prohibitively unable to consume Apple's media offerings on the go.

The future

All the problems I listed here are not insurmountable, even in the short term. But releasing a device with such a display would either be half baked, prohibitively expensive, or likely both. And Apple's philosophy isn't to make products because they can, but to make products because they make sense. The iPad Unicorn simply doesn't make sense. Not now, not six months from now, not a year from now, not 18 months from now.

But let's talk about it for the third revision of the iPad in 2012. For now, that iPad you just bought will do just fine for a long time to come.

Updates

Update 1

Kevin Fox correctly notes that the optimal viewing distance of an iPad is likely larger than for an iPhone, so it would not necessarily need to have the same pixel density to achieve the same end result (no discernible pixels). Even at his suggested 260 ppi, it's still over the amount needed for 1080p. While 1080p video would likely look fine on such a device, the other problems still remain.

Let's take this further, though. Based on Phil Plait's measurements, if we assume a 24" viewing distance (not a bad distance if it's sitting in your lap), you'd only need a 144 ppi display in order to qualify as a "retina display" in the sense that the pixels are no longer discernible. At 131 ppi right now, the current iPad is not that far off.

Based on this, I'd still say talk of a game-changing iPad by January is still overblown (if less ludicrously so). If you look at the product development of the iPhone, Apple stayed with the same display, even while other comparable phones were getting better ones, until it could release the retina display. It's highly unlikely they'd change the display within a year (or two) for a minor upgrade that would cause even more display fragmentation.

As I said above, Apple doesn't release products because they can, they release products that make sense.

Update 2

The rumor has risen from the grave a few times since publishing this article, but now in January 2011, MacRumors is predicting that iPad 2—due for release in the next few months—will have a resolution of 2048x1536. Everything I said above still stands, even at this (slightly) reduced prediction: nothing about bandwidth, costs, or technology has significantly changed in the past six months. Instead, basing the prediction entirely on new assets found in a recent version of iBooks, people are hoping Apple has invoked dark incantations to magically solve all the technology problems.

But I have a far more mundane interpretation: Apple is thinking medium term. Obviously, at some point, the iPad will get an updated, higher resolution display. Adding the new "X2" assets allows Apple to test its assumption that the same tricks it used for the iPhone retina display—supporting two resolutions without issue because the new resolution is exactly quadruple the old resolution—will work. I wouldn't even doubt that Apple will publish a guide imploring developers to do the same and think towards the future: it wouldn't be the first time Apple published a guide for something years before it becomes a reality.6

Update 3

Sure enough, on March 2nd, 2011 iPad 2 was released without a Retina display.

Update 4

It's March 2012 now, and Apple finally released a Retina display-equipped iPad at a resolution of 2048×1536 at 263 ppi. My powers of prognostication are available for Bar Mitzvahs and children's birthday parties.


  1. Apple eventually released a 1680×1050 MacBook Pro in 2011, and a MacBook Pro with Retina display, sporting 2880×1800 pixels, in 2012. 

  2. Apple discontinued the 24" LED Cinema Display in 2011, leaving only the 27" Thunderbolt Display with a resolution of 2560×1440 pixels. 

  3. 4K resolution video, with standards starting at 3840×2160 pixels, began to see partial adoption in 2011. 

  4. In hindsight, Apple "solved" this problem by ignoring this and making the Retina display-equipped iPads slightly thicker than iPad 2. 

  5. Specifically, Star Trek (2009). With the release of the first Retina display-equipped iPad in 2012, Apple began to release 1080p videos using better compression; Star Trek in this format is 4.81 GB. 

  6. Originally, I linked to Apple's recommendations for HiDPI displays, first published circa 2006 or 2007. Apple doesn't seem to care about link rot and took the guide down when the first Macs started shipping with Retina displays. 


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