Windows 8 provides a new mobile user experience and supports key areas of innovation in graphics hardware and software that benefit end users, developers, and system manufacturers. The best visual experience in Windows 8 is delivered with the latest graphics hardware paired with an optimized Windows Display Driver Model (WDDM) version 1.2 driver.
Windows 8.1 Preview adds several new features to improve GPU performance, to send video wirelessly to a Miracast-enabled display, and to let apps specify extended range YUV formats. WDDM 1.3 drivers are needed to enable these features. See What's new for Windows 8.1 Preview display drivers (WDDM 1.3).