were unveiled at WinHEC 2008. New features include: DXGI 1.1, which features return of hardware 2D acceleration for use by GDI (but not GDI+) and Direct2D/DirectWrite BitBlt, StretchBlt, TransparentBlt AlphaBlend, ColorFill ClearType font support Direct3D 11 device driver interface (DDI) DXVA-HD DDI Hardware video overlay DDI Optional AES 128 encryption Optional decoding of encrypted video content Support multiple drivers in a multi-adapter and multi-monitor setup Hardware acceleration of GDI and Direct2D/DirectWrite operations helps reduce memory footprint in Windows 7, because DWM compositing engine no longer needs to keep a system memory copy of all surfaces used by GDI/GDI+, as in Windows Vista. DXGI 1.1, Direct3D 11, Direct2D, and DirectWrite were made available with Windows Vista Platform Update; however GDI/GDI+ in Vista continues to rely on software rendering and the Desktop Window Manager continues to use Direct3D 9Ex. WDDM 1.1 drivers are backward compatible with WDDM 1.0 specification; both 1.0 and 1.1 drivers can be used in Windows Vista with or without the Platform Update. WDDM 1.2 Windows 8 includes WDDM 1.2 and DXGI 1.2. New features were first previewed at the Build 2011 conference and include performance improvements as well as support for stereoscopic 3D rendering and video playback. Other major features include preemptive multitasking of the GPU with finer granularity (DMA buffer, primitive, triangle, pixel, or instruction-level), reduced memory footprint, improved resource sharing, and faster timeout detection and recovery. 16-bit color surface formats (565, 5551, 4444) are mandatory in Windows 8, and Direct3D 11 Video supports YUV 4:4:4/4:2:2/4:2:0/4:1:1 video formats with 8, 10, and 16-bit precision, as well as 4 and 8-bit palettized formats. WDDM 1.2 supports display-only and render-only WDDM drivers, such as Microsoft Basic Display Driver and WARP-based Microsoft Basic Render Driver which replaced kernel-mode VGA driver. WDDM 1.0/1.1 only allows rudimentary task scheduling using "batch queue" granularity; improvements to multitasking, as well as fast context switching and support for virtual memory, were initially expected in versions tentatively named WDDM 2.0 and WDDM 2.1, which were announced at WinHEC 2006. WDDM 1.3 Windows 8.1 includes WDDM 1.3 and DXGI 1.3. New additions include the ability to trim DXGI adapter memory usage, multi-plane overlays, overlapping swap chains and swap chain scaling, select backbuffer subregion for swap chain and lower-latency swap chain presentation. Driver feature additions include wireless displays (Miracast), YUV format ranges, cross-adapter resources and GPU engine enumeration capabilities. Graphics kernel performance improvements. WDDM 2.0 Windows 10 includes