When Apple raises the curtain on its big show this Wednesday, it’ll unveil the iPad 3, which will almost certainly have a retina display that features a pixel count of 2,048 x 1,536 — a truly amazing spec for a tablet. But is such a high-resolution screen really necessary?
Yes, per usual, Apple hasn’t said word one about what’s going on this week, whether it’ll unveil a new iPad or even if there is a new iPad. But there have been enough rumors, leaks, and logical predictions that the iPad 3 will have a retina display. A photographic analysis of Apple’s event invitation even appears to show a higher-resolution screen than the current iPad.
How can we know the resolution so precisely? Besides the numerous reports, the spec exactly doubles the vertical and horizontal pixel counts of the current iPad, whose resolution is 1,028 x768 (producing four times the actual resolution, since area varies as the square of the dimensions). It makes a lot of sense Apple would aim for that spec, since it’s exactly what the company did when it increased the screen resolution of the iPhone when it unveiled the iPhone 4. Doubling the resolution makes it extremely simple to scale up apps an other software.
However, it also makes many other things harder. Rendering that many pixels — 3,145,728 of them, in fact — puts more strain in the processor, the backlight and the battery. It also puts pressure on Apple’s display manufacturing partner to produce quality screens in the volumes that Apple demands.
Extreme Screen Measures
On the eve of the iPad 3′s unveiling, it bears reminding what an ungodly number of pixels a 2,048 x 1,536 is for the iPad’s 9.7-inch screen. Most desktop monitors don’t go that high. A screen that dense would mean 1080p video — currently the highest-resolution video format in mass use — would use only two-thirds of the pixels available on the screen.
“Have you ever used a 9.7-inch display with that high resolution?” asks Raymond Soneira, president of display-research company DisplayMate. “Most people don’t even have 1,600 x 1,200 on their desktop monitors. From a purely objective, practical point of view, yes, it’s visually an overkill.”
So why would anyone want so many pixels in a mobile device? Simple answer: marketing.
“I think 2,048 x 1,536 is a marketing reality,” says Soneira. “Marketing displays is like marketing megapixles in cameras. Consumers buy specs. But it also makes it a no-brainer to take legacy 1,024 x 768 [software] and make it run at 2,048 x 1,536.”
Sea of Pixels
Although developers will only need mastery of simple arithmetic to scale up their apps for the iPad 3, the huge leap in pixels will mean virtually ever aspect of the tablet will need an upgrade.
“You’re pushing four times as many pixels,” says Soneira. “So you need for times as much processing power. You also have to devote four times as much memory to the display as before — and that’s not just a single screen. The processor keeps many more than a single display frame buffer inside its memory, as it does video, animation and all kinds of other caching. Then the display itself takes more power. The efficiency, the amount of light that goes through the display goes down, so your power has to go up to back-light the display.”
By all reports, that’s exactly what Apple has done — completely re-engineer the iPad to run at the higher resolution, including a faster processor, bigger battery and all the other hardware the display will need. But did Apple have any other option but to double the resolution in both directions? Soneira thinks there was a less extreme solution: sub-pixel rendering.
In a typical LCD, every pixel has an red, green and blue component — the sub-pixels. When a pixel gets visual data, it displays what it’s told with those three elements and nothing more. But with sub-pixel rendering, the display can task nearby sub-pixels to give better detail over what’s displayed. The technique is used in Microsoft ClearType.
“There are very good quality scaling engines,” he says. “So if you made it, say, 1,600 x 1,200 and used sub-pixel rendering, it would do just fine. Actually, the current 1,024 x 768 display would look substantially better if you do sub-pixel rendering.”
The Future of Retina
The opportunity such a compromise appears to have passed, however, and Apple is poised to unveil a retina-display iPad. In fact, it could lead to retina displays becoming the norm on all Apple products, including the MacBook Airs and MacBook Pros. Although Apple can’t win on every spec, having retina screens across the board would give it an across-the-board differentiator.
“Steve Jobs, with this whole retina display, really elevated the whole display business,” says Soneira. “It was a brilliant marketing move. It set up a ‘display race.’ I just hope we don’t keep going [higher] in resolution.”
Do you think a retina display in the iPad 3 is overkill? Let us know your thoughts in the comments.
BONUS: Could iPad 3 Cost More Than iPad 2?
1. Retina Display
All reports point to an iPad 3 with a screen that doubles the pixel resolution in both directions. While that would be an incredible amount of pixels (more than what's needed to even show 1080p video at full resolution), it's also going to be harder -- and more expensive -- to make such a large-size "retina display." And if Apple goes with a new kind of LCD tech (like Sharp's IGZO), all bets are off.