Microsoft explains how Windows 8 smokes Windows 7

Microsoft spelled out acceleration improvements in Windows 8, in a blog post Monday. Needless to say, Microsoft says the overall experience is a lot snappier.

The latest Building Windows 8 entry, penned by Rob Copeland, the group program manager at Microsoft's graphics team, is titled Hardware accelerating everything: Windows 8 graphics.

Some context is first provided at the top in order to illustrate how Window 8 "builds on the well-established foundations of DirectX graphics" in Windows 7.

In Windows 7, we expanded the capabilities of DirectX to provide a common hardware-accelerated graphics platform for a broader range of applications. Whereas previously, DirectX mainly provided 3-D graphics, we added functionality for what we call "mainstream" graphics. Mainstream uses [include] web browsers, email, calendars, and productivity applications...With these additions, DirectX became a hardware-accelerated graphics platform for all types of applications.

Some highlights of the blog:

• Internet Explorer 9 as a starting point: Because Internet Explorer 9, Windows Live Mail, and Windows Live Messenger make "excellent" use of DirectX, they're good examples of what other apps might do. "This led to a number of investments to ensure mainstream apps were fast and looked great."
  
• Text acceleration: Text is used a lot in Windows, so accelerating text rendering in Web pages, email programs, and instant messaging is a high priority. Microsoft says it has continued to improve text performance in Windows 8. (See graph and link to video below.)
  
• Geometry rendering: Microsoft also made "dramatic performance improvements for 2D geometry rendering." Geometry rendering is used to create tables, charts, graphs, diagrams, and user interface elements. For Windows 8, improvements "have primarily focused on delivering high-performance implementations of HTML5 Canvas and SVG technologies for use in Metro style apps, and webpages viewed with Internet Explorer 10." (See graph and link to video below.)
  
• Image rendering:"Several improvements" have been made for working with images and photographs using the JPEG, GIF, and PNG formats. Improvements include "Faster image decoding by expanding SIMD usage on all CPU architectures." (See link to video below).
  
• Example of rendering improvement: When video is playing, the browser must update the portion of the window containing the video but not the text. "To improve apps that don't need to redraw the entire screen for each frame, we optimized how DirectX deals with redrawing just portions of the screen and how it scrolls." This "reduces the number of times graphics data needs to be copied in memory, it also reduces power consumption, thus increasing battery life."
  

In a video, Rob Copeland illustrated the performance improvements covered in the blog.