indows 8, Microsoft innovative and controversial new consumer operating system (OS) is set to hit store shelves and go live online on October 26.
Available in three varieties (Windows 8, Windows 8 Pro, and the ARM-compatible Windows 8 RT), the new operating system seems like it would be a performance killer with demanding multi-touch (even on new desktop machines!) and the rich, colorful animated Metro user interface (UI). But despite the demands of the new gloss, Microsoft has thus far showed a stubborn determination to not just meet Windows 7's already high performance bar, but to surpass it.
I. Improving Metro UI and Image Rendering
Microsoft in one of its Building Windows blogs highlights the TLC it has been giving to DirectX, its graphics API.
The company has focused on improving five metrics:
- Framerate (Microsoft's target is a steady 60 Hz or higher)
- Glitches (tearing, dropped frames, and other artifacting)
- Initialization Time (time to load graphics resources onto device from time app is clicked)
- Memory (Microsoft wants to try to cut system-side memory usage while preserving performance)
- CPU (Microsoft wants to load the CPU less)
With Windows 7, Microsoft's efforts focused on DirectX acceleration of Internet Explorer 9, Windows Live Mail, and Windows Messenger. With Windows 8, it's now looking to accelerating all Metro apps.
It reports that text rendering has improved between 150 and 330 percent from Windows 7 -- critical because Metro UI uses a lot of rich word art to convey information. Metro UI also uses a lot of rich geometry, rendered as HTML5 Canvas and SVG standardized technologies. Microsoft reports drawing lines nearly twice as fast and rectangles over 4 times as fast as in Windows 7.
SVG is a bit trickier than standard geometry, as SVG images can be irregular shapes -- such as the outline of an animated cartoon animal. For SVG Microsoft has baked a new acceleration technology called Target Independent Rasterization, or TIR, into DirectX 11.1's Direct2D libraries. Microsoft promises between 150 and 500 percent improvement over Windows 7 in rendering rates.
Direct2D also has received hardware acceleration for Direct2D Effects, which allow for certain pseudo-3D or noise based graphical flourishes. These can help application developers make more attractive components and transitions within their user interfaces.
Microsoft has also improved rendering of JPEG, PNG, format conversion, image scaling and more. A key to these improvements has been to leverage the fact that most compressed graphics formates (e.g. JPEG, PNG) use repetitive operations on data, hence are ideal candidates for Streaming SIMD (Single Instruction Multiple Data) Extensions (SSE) on x86 (Intel or AMD) processors. The net result here is that viewing, zooming, and editing images in Windows 8 and Windows 8 Pro will be much faster than in Windows 7, thanks to native API improvements.
II. Cutting Power Consumption in Mobile Devices, Improving Gaming
By reducing memory usage and CPU usage, Microsoft can preserve battery life on mobile devices. To do this, it employs two new develops. The first is reduced precision blending. Microsoft observed that when blending multiple transparent layers, virtually no difference is observed when reducing the number of bits used from 32 bits to 10 bits. As blending is a common task performed on hundreds of graphics every frame in many apps, reducing the precision can result in big savings.
A second strategy is to use so-called "tile-based rendering", an approach that loads a piece of the screen to be rendered into a high-speed memory cache, and then have the GPU perform repetitive operations on it. The repetitive operations reduce the GPU's power draw; while the use of cached memory eliminates the need for an external memory buffer, further cutting power consumption.
Gaming-wise, Microsoft mentions that it has made it easier for developers to blend 2D and 3D effects, as DirectX 11.1 now uses a single rendering object, eliminating the need to switch between rendering modes. This will allow for less expensive rendering of certain objects in games, such as 2D heads up displays (HUDs).
Microsoft doesn't otherwise delve very deeply into what kind of gaming improvements it is baking into DirectX 11.1, but as an innovator in this field, Microsoft will likely have some neat tricks. The company works closely with graphics professionals like id Software founder John Carmack, individuals who are quite literally defining the state of the art in graphics rendering techniques.
Expect more details on the gaming improvements to pile on in the weeks to come.