The oft-rumored 12.9-inch 'iPad Pro' could feature a 2732x2048 display, according to evidence found in the first iOS 9 beta. Developers Hiraku Wang and Steve Troughton-Smith point to code in the beta that refers to a 1366x1024 device, which implies a true resolution of double that using @2x scaling.
That works out to a display area of roughly 12.93 inches and a PPI of 263, which lines up with previous reports. In January of last year, NPD DisplaySearch cited supply chain sources, saying that Apple had a tablet in development with a larger 12.9-inch display, a resolution of 2732x2048 and PPI of 265.