Developer(s) | Microsoft |
---|---|
Initial release | March 2005 | (announced)
Operating system | |
Platform | x86, x86-64 |
Type | Computer performance measurement |
Website | Windows System Assessment Tool at MSDN |
The Windows System Assessment Tool (WinSAT) is a module of Microsoft Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows 10, and Windows 11 that is available in the Control Panel under Performance Information and Tools (except in Windows 8.1, Windows 10, and Windows 11). It measures various performance characteristics and capabilities of the hardware it is running on and reports them as a Windows Experience Index (WEI) score. The WEI includes five subscores: processor, memory, 2D graphics, 3D graphics, and disk; the basescore is equal to the lowest of the subscores and is not an average of the subscores.[1][2] WinSAT reports WEI scores on a scale from 1.0 to 5.9 for Windows Vista,[3] 7.9 for Windows 7,[4] and 9.9 for Windows 8, Windows 8.1, Windows 10, and Windows 11.[5]
The WEI enables users to match their computer hardware performance with the performance requirements of software. For example, the Aero graphical user interface will not automatically be enabled unless the system has a WEI score of 3 or higher.[6][7]
The WEI can also be used to show which part of a system would be expected to provide the greatest increase in performance when upgraded. For example, a computer with the lowest subscore being its memory, would benefit more from a RAM upgrade than adding a faster hard drive (or any other component).[2]
Detailed raw performance information, like actual disk bandwidth, can be obtained by invoking winsat
from the command line. This also allows only specific tests to be re-run.[8] Obtaining the WEI score from the command line is done invoking winsat formal
, which also updates the value stored in %systemroot%\Performance\WinSAT\DataStore
.[9] (The XML files stored there can be easily hacked to report fake performance values.[10]) The WEI is also available to applications through an API, so they can configure themselves as a function of hardware performance, taking advantage of its capabilities without becoming unacceptably slow.[11]
The Windows Experience Index score is not displayed in Windows 8.1 and onwards because the graphical user interface for WinSAT was removed in these versions of Windows, although the command line winsat tool still exists and operates correctly along with a final score when launching the command "shell:games".[12] According to an article in PC Pro, Microsoft removed the WinSAT GUI in order to promote the idea that all kinds of hardware run Windows 8 equally well.[13]