The new Sony Xperia Z5 Premium which was announced at IFA is the first production smartphone with a 4K display. Its 3840 x 2160 pixels are distributed over a 5.5-inch screen, resulting in an unrivaled pixel density of 806 ppi. However, Sony also claims the new device offers approximately two days of battery life on a single charge, which contradicts the popular belief that higher resolution displays consume more battery power. 

Sony has now released a statement to PhoneArena, explaining the apparent discrepancy: 

Xperia Z5 Premium features a 4K display with a resolution of 3840×2160 pixels based on SID Standard and enables all video and image content to be enjoyed in 4K resolution. All other content is displayed at 1080p or lower resolution in order to optimise the performance and battery stamina for this device, ensuring you can enjoy the 4K resolution when you need it most.

So Sony has done the smart thing and only uses the 4K resolution when it actually matters: image and video viewing. Gallery and video playback apps are rendered at 4K resolution, everything else, including home screen, web browser, productivity apps and games are displayed at 1080p Full-HD resolution. This makes a lot of sense, as arguably viewing app icons or web pages at 4K would not offer a better experience over Full-HD. It'll be interesting to see what other manufacturers will implement 4K displays in their mobile devices and how they will deal with the battery dilemma.

Via: Phone Arena