Windows Experience Index: Overview
Windows Vista is a scalable operating system that turns features on/off based on the performance ability of the hardware to perform scenarios well. Therefore, it is designed to take full advantage of the latest high-end equipment, while at the same time is able to run well on less capable hardware.
Because performance is important to delivering the advanced scenarios and applications being developed today, Windows Vista also includes a new system designed to help average users simplify those performance considerations as part of the PC, hardware upgrade and software purchasing process called the Windows Experience Index (formerly named Windows System Performance Rating or WinSPR). The Windows Experience Index provides the user or administrator with a high-level assessment of a given machine's performance capabilities expressed as a number 1-5. This number is an easy-to-use metric that indicates what scenarios and applications a user can expect will perform well on a given Vista machine based on its performance characteristics. Windows Experience Index will help users and administrators assess the performance capabilities of a given system, ultimately making it easier to buy or upgrade PCs and software that match their needs.
The backbone for the Windows Experience Index scores comes from the same new technology built into Windows Vista that enables it to scale, called Windows System Assessment Tools (WinSAT). These tools run tests that discover and assess the performance characteristics and capabilities of a PC. Based on this data, Windows Vista "scales" itself, thereby optimizing the user experience and feature level it delivers for a given computer. The WinSAT data is also available via the Win32 API in order to enable software vendors and internal developers to take advantage of WinSAT data in order to develop software which determines the optimal application settings based on that system's performance capabilities and scale itself.
The following is designed to answer common questions about Windows Experience Index, and help customers understand how to use and manage this feature in their organizations.
Q. How does Windows Vista help address the complexity of the varying PCs' capabilities in an enterprise's network?
A. We designed Windows Experience Index to be primarily a tool for consumers and general users who are not "techies". That said, enterprises can make use of WinSAT in their LOB applications, and from a systems management perspective, by knowing what percentage of their machines are in each Windows Experience Index level and sourcing machines appropriate to their users' needs.
Q. Can I override the feature scaling of Windows Vista?
A. Yes, an administrator can override the defaults and turn on/off scalable features, although system performance and stability may suffer if they do so.
Q. What does WinSAT measure?
A. WinSAT measures five key areas of a PC's hardware: desktop graphics, 3D business (Avalon apps) and gaming graphics, system memory throughput, sequential read throughput in the storage system, and CPU processing speed and ability. Desktop graphics assessments are focused on the ways a window on the desktop displays and moves. Gaming graphics assessments are focused on the 3D capability of the computer. In Windows Vista, the 3D capability of the computer is vital to the Aero interface and Avalon-based applications.
Q. When does WinSAT run?
A. On all new installations, WinSAT will run and be displayed as part of the installation process and the appropriate defaults for scalable features are determined. WinSAT can also be run via the Performance tools located in the control panel or via the API when software installs. This is particularly helpful when an administrator installs a new hardware and the installation program initiates a new WinSAT run to get updated results.
Q. What is Windows Experience Index and why are there only 5 numbers?
A. The Windows Experience Index provides the user or administrator with a high-level score of a given machine's overall performance capabilities based on the 5 categories analyzed by WinSAT and assigns that computer a Windows Experience Index score from 1 to 5. Windows Experience Index will make it easier for administrators to buy or upgrade PCs and software that meets their users' needs. For example, a PC with a Windows Experience Index of 5 can perform intensive graphics functions and run any software with a Windows Experience Index of 5 or below.
At this time, there are 5 scores on the Windows Experience Index scale (1 being the most basic PC, 5 being the most advanced PC); however, as new technologies and advancements come to market, this scale will be expanded to higher numbers. The existing numbers will simply remain defined 'as-is' (i.e., the performance metrics for a 3 will always be the same regardless of how many new numbers are added). We created this score system with upward scalability and hardware advances in mind.
Q. How are new Windows Experience Index levels added?
A. As new advancements in graphics, processing, memory, and storage come to market, we will assess how those new technologies advance the ability of a PC to perform more advanced functions enabling new usage scenarios and add new numbers to the scale as appropriate. For planning purposes we expect that approximately one new number would be added every 12-18 months, but technology innovation and scenario enablement will drive the introduction of new scores, not the calendar.
Microsoft will continue to work cooperatively with our partners in setting future Windows Experience Index scores and thresholds.
Q. How can I view a computer's Windows Experience Index?
A. Windows Experience Index is displayed when you first install Windows Vista. After installation, the Windows Experience Index can be found as part of the Performance Tools in the Control Panel, in the Welcome Center and in the Main System Control Panel. It is also referenced in other areas of the user interface.
Q. How do the Windows Experience Index sub scores accrue to the Base score?
A. When you think about experiences on a PC, all performance-related sub-systems are required for delivery. High sub rated CPU, Memory, and Hard Disk (i.e., all 4.0 or higher) cannot make up for a weaker graphics card (i.e., a 2.2 sub rated graphics card) when it comes to delivering an intensive media experience (i.e., playback of HDTV or running multiple monitors). Therefore, using a simple average of the sub scores does not accurately reflect the overall performance of a PC to deliver advanced experiences. For this reason, the base score determined by the lowest scoring sub-system component.
Q. How can 5 numbers really encompass the broad array of things people do with their PCs? Don't you need 10 or 20 levels?
A. For most applications, performance on a given PC is determined by five key resources: memory, processing, desktop graphics, 3D graphics, and storage. We have found that for PCs running Windows Vista, nearly every application on the market today fits within 5 thresholds on these key resources for peak performance. Furthermore, we built Windows Experience Index to be upwardly scaled, so that as machines become more capable more levels can be added.
Q. Windows Experience Index does not seem to rate any mobile-specific features such as battery life, weight, form factor, etc. How does Windows Experience Index apply to laptop machines?
A. Windows Experience Index is an indicator of system performance capabilities. It is not an overall assessment of the machine's goodness or fitness for a given purpose. Windows Experience Index is but one factor in determining what a person needs from their PC. There are many other criteria that should influence a purchase decision. These include factors such as battery life, form factor (including size and weight), screen size, home network capabilities, monitor type, DVD or CD read/write capabilities, industrial design, number and type of ports, radio stacks, etc. And of course price is always a consideration.