If the iPhone expected to be announced on September 9 has a bigger screen — and that certainly seems likely — one major unanswered question is what the resolution of the bigger screen will be. A new tidbit unearthed in the latest Xcode SDK beta indicates that the new iPhone could have a 828 x 1472 screen, which would add both horizontal and vertical screen space to Apple’s iOS interface.
The additional pixels open up the possibility of additional rows or columns of icons on the home screen, although there is no indication that Apple is planning to change from the 24-icon home screen layout currently used on the iPhone 5S.
The hint was found in an iOS 8 file defining where icons go on the iPhone home screen, Mark Gurman at 9to5Mac reports. The file itself describes an iPhone home screen with an effective resolution of 414 x 736, which results in a 828 x 1472 resolution when doubled per Apple’s current method of handling Retina displays. Previous reports have indicated that Apple is toying around with a “pixel-tripling” mode, which indicates that 1242 x 2208 is a possible resolution as well.
The new resolution would not only add vertical pixels, the way Apple did with the iPhone 5, but would add horizontal screen space as well. The screen would retain a 16:9 aspect ratio, which matches up with the parts leaks we’ve seen so far. However, the additional pixels added to the effective resolution could end up being a headache for developers because it would require additional work to update apps for the newest iPhone.
Back-of-the-envelope calculations and previous reports have pointed to other candidates for the new iPhone resolution. Currently, developers work with a 320 x 568 default screen size for the iPhone 5S, which results in a 1704 x 960 resolution when tripled. The advantage to that approach is that it would be easier for developers.
There is one handy smell test for possible iOS screen resolutions: Do they end up exceeding the arbitrary Retina display cutoff of 300 pixels per inch? Turns out a 828 x 1472 resolution would qualify as a Retina display at both 4.7 and 5.5-inch screen sizes.
Regardless, Apple has made its decision about the resolution of the latest iPhone (or iPhones), because it is already in production. We’ll know which approach they decided to go with on September 9.