David Barnard of TUAW has written an excellent article about why it may not be necessary for Apple to manufacture devices that are Retina Display. The key takeaway from Barnard’s post is that PPI is much less relevant on OS X than on iOS. To create Retina displays, Apple does not have to build displays that are exactly 2X current displays. Below is an excerpt from Barnard’s post:
The point is, PPI is much less relevant on OS X than on iOS. To create Retina displays, Apple doesn?t have to build displays that are exactly 2X current displays, they just have to build displays that work well with OS X when running @2X. For example, the current 27-inch iMac is 2560?×?1440 pixels, which translates to 109ppi. Doubling that to 5300?×?2880 pixels is not strictly necessary. Such a screen might be incredibly difficult to manufacture, and therefore incredibly expensive. Instead, Apple could build a 3840?×?2400 pixel 27-inch screen that presented itself as a pixel doubled 1920?×?1200 pixel display. That?s effectively an 84ppi screen @1X and 168ppi screen @2X.