You may not realize it, but the new Apple A8 processor on the latest iPhone 6 and iPhone 6 Plus can handle 4K video playback even though the smaller Apple phone has a native resolution of 1334 X 750 pixels while the larger Plus model has a 1080p Full HD display with 1920 X 1080 pixels. Though you won't get a pixel-for-pixel output on the phones' screens, the A8's ability to handle 4K playback means that users who sideload 4K content would be able to still watch it on their phones.