Apple's latest little iPad packs the same number of pixels as its biggest. The 7.9-inch Retina display is an IPS panel with a resolution of 2,048-x-1,536. That's a density of 326 pixels per inch. The 8.9-inch diagonal LCD of the Kindle Fire HDX (pictured) puts out 2,560-x-1,600, or 339 ppi. At resolutions this high, the human eye is incapable of discerning the pixels on either panel. Let's call them both amazingly accurate and lifelike.