The 12.9-inch model has a 2732-by-2048 Retina Display at 264 pixels per inch, and the 9.7-inch model has a 2048-by-1536 Retina Display at 264 pixels per inch and features a variable refresh rate, a first for Apple. The 12.9-inch version of the iPad Pro is the first iPad to include 4 GB of RAM.