Why a Retina Display on a MacBook could be a bad idea

The most-rumored new MacBook update sounds like it might be more trouble than it's worth.

A simulated 2,560x1,600-pixel non-HiDPI screenshot of your favorite Web site on a 15-inch MacBook Pro (although a Retina MacBook would probably not look like that). Dan Ackerman

One of the most persistent rumors about possible upcoming new Apple MacBook laptops (aside from a 15-inch MacBook Air or the end of the 17-inch MacBook Pro) is that they will include upgraded high-resolution Retina Displays, like those on the iPhone 4/4S and third-generation iPad.

But, would this fairly significant change be worth it? If Apple breaks from the laptop norm (for example, by upgrading the 15-inch MacBook Pro's 1,440x900-pixel display to a purported 2,560x1,600 pixels), I'd have concerns about battery life, system size and weight from a potentially larger battery, and even price, as higher-resolution panels cost $100 more by some estimates. And consumers could be confused if Apple breaks a long-standing tradition of how laptop screen sizes and screen resolutions relate.

The current high-end resolution for laptops is 1,920x1,080 pixels, which we sometimes refer to as full HD or 1080p -- that's the same as Blu-ray HD video. On a 17-inch desktop-replacement laptop, it's great, and it mostly works on a 15-incher as well. The handful of 13-inch laptops with 1,920x1,080-pixel screens I've seen are hard to read. For even higher resolutions, Apple would have to have a workaround for this. The most likely way a Retina MacBook would work would be using HiDPI. My colleagues Josh Lowensohn and Brooke Crothers explain:

If Apple bumps up the resolutions on these displays and keeps them the same size, it has to treat pixels differently using a a special mode called HiDPI. The feature understands that there are more pixels, but that the scale of the display is the same. Apple added the feature to its OS X 10.7 software last year, but it isn't readily available to users. Some third-party software, including the recently-updated Air Display app for iOS have unlocked it so that users can try it out on their third-generation iPad.

Most MacBooks are already outside of the laptop resolution mainstream, with 16:10 screens on everything except the 11-inch MacBook Air, which is the company's only 16:9 laptop. As these are some of the only 16:10 laptops left, some kind of change wouldn't be surprising.

Even if Apple trades up to a much higher resolution than any other laptop but still manages to keep things readable, that would mean resolution and screen size alone would no longer give you a fixed idea of what content (Web sites, games, photos, etc.) would look like on a laptop screen. This could make comparison shopping confusing, and it would be another example of different computer manufacturers using different standards.

For example, today I could easily tell someone shopping for a laptop that a good sweet spot to look for in a premium 13-inch laptop is a screen resolution of 1,600x900 pixels. In the future, would I have to suggest 1,600x900 if a laptop is from one list of PC makers with one type of DPI technology, and a second set of recommended resolutions for brands that use different DPI settings? Good luck fitting all that on the shelf tag at a brick-and-mortar retailer.

On top of that, as we saw with the third-gen iPad, the implications for battery life (and therefore battery size) are real, which is especially important in the slim MacBook Air models. A Retina Display would likely need more power, which would lead to either a bigger battery (and thicker chassis) or shorter battery life, or both. The MacBook Air is near-perfect as is. Mess with the size, weight, or battery life at your own peril.

Of course, crisper text and sharper images is not a bad thing, and if it gives consumers a notably better overall experience, that could mitigate my concerns. But, I have to admit, in many years of reviewing laptops, no shopper has every told me he or she wanted a screen resolution higher than 1,920x1,080.

Do you think new MacBook laptops need a 2,560x1,600-pixel display? Would it be worth less battery, more weight, or a higher price? Post your opinion in the comments section below.

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