Graphics improvements
Nearly all of the desktop and Start-screen functionality now relies on acceleration from your machine’s graphics processing unit. Many of Windows 8’s windows subsystems use the DirectX API. HTML5 and SVG (scalable vector graphics) also depend on GPU acceleration, in the form of enhanced 2D geometry rendering. Applications tell Direct2D what to draw in the form of 2D objects, such as circles and rectangles, plus additional features such as color and style. The API converts the instructions into a format suitable for Direct3D, which passes the instructions to the GPU. As a result, normal desktop windows will likely see substantial performance increases.
On top of that, Microsoft has added a new programming interface, DirectText, which offloads text rendering to the GPU. Text-rendering performance in desktop programs and in Windows 8 apps is double that of Windows 7—often better than double.
Why, then, did Microsoft return to “flat” windows, eliminating the transparency and other 3D effects it used in previous editions of the OS? Direct2D and Direct3D will also work with Windows RT and Windows Phone 8, and removing the eye candy will help Windows perform equally well across diverse platforms.