In a little more than three months, Windows 8 will be released to the public. Microsoft has done a great job of detailing various aspects of the operating system in its Building Windows 8 blog, and the latest entry provides a look at the hardware-accelerated graphics tweaks built into the OS. Graphics performance is a priority for Win8, and Microsoft created new test metrics to ensure a smooth experience for end users. In addition to targeting a 60 FPS frame rate for OS-related visuals, Microsoft started counting glitches, which it defines as frames that take longer than 16.7 milliseconds to render. Looks like someone's been paying attention to our Inside the Second game benchmarking methods.
Microsoft's graphics optimizations focus more on OS elements and applications than on 3D games. Time has been spent tweaking DirectWrite to speed text rendering, and tessellation performance has been improved for simple geometry like rectangles and ellipses. JPEG and PNG images should decode much faster on the new OS, as well. You can see some of the benefits on display in the video embedded below.
Windows 8 will include an update to DirectX, version 11.1, that supports a new Target Independent Rasterization (TIR) feature included in the latest GPUs. Microsoft says TIR uses fewer CPU cycles when tessellating irregular geometry, such as geographic borders or the spinning fractal on display at the end of the video.
Although it's not mentioned in the video, Microsoft has also added Direct2D Effects, a set of libraries that will be exposed to developers through a puportedly simple API. These effects can be applied to any image and should make app interfaces a little snazzier. However, it looks like the effects could be limited to Metro. Ugh.
Tablets and other Metro-centric devices with relatively low-end hardware seem the most likely to benefit from Win8's graphics tweaks. I'm eager to see how the OS feels on an Atom- or even ARM-powered tablet. With Apple devices famous for their smooth user experiences and Jelly Bean dramatically improving Android responsiveness, Windows 8 and its RT offshoot have their work cut out.