You would have noticed a column named “Startup Impact” in Task Manager’s Startup tab in Windows 8 and higher. But what does “Startup Impact” mean and how is it assessed?
Task Manager Startup tab lists all startup apps loading from Run, RunOnce registry keys and from the user’s Startup folder, and allows the user to disable unneeded startup programs. Task Manager also displays the “Startup Impact” of each startup program. The Impact rating is based on the program’s CPU and disk usage at startup.
Per Microsoft: Startup apps (Windows), the following criteria is applied to determine the Startup Impact values for each startup entry.
- High impact – Apps that use more than 1 second of CPU time or more than 3 MB of disk I/O at startup
- Medium impact – Apps that use 300 ms – 1000 ms of CPU time or 300 KB – 3 MB of disk I/O
- Low impact – Apps that use less than 300 ms of CPU time and less than 300 KB of disk I/O
So, OneDrive.exe (OneDrive client) in the screenshot above clearly qualifies for being in the “High Impact” category.
It shows the Impact as “Not measured” for entries pointing to a missing file, or haven’t clocked a single run yet, via Startup. Impact shows up as “None” for disabled entries in the Startup tab.
How does Windows Measure the “Startup Impact”?
The “Startup Impact” is actually calculated by the Windows Diagnostic Infrastructure. Windows runs a boot trace every time you start your computer, and the results of which are stored in a event trace file named “Bootckcl.etl” in this directory:
If you want to analyze this file, you need Windows Performance Analyzer (WPA) installed in your system. This tool is part of the Windows Assessment and Deployment Kit which can be downloaded from Microsoft site. WPA is an extremely useful tool to troubleshoot slow boot and performance issues in the system.
Based on the boot trace, Windows also generates separate XML files in the “LogFiles\StartupInfo” directory which contains details about each startup item, their start time, CPU time as well as the Disk Usage at startup for each user. The XML file is separate for each user, and the file name includes the user account’s SID, such as the following:
You can open these files using Notepad, and check out the readings there. To find the appropriate file for your user account, you need to first find your user account SID by typing
whoami /user in a Command Prompt window. There are several ways to find out your SID, but
whoami is probably the easiest.
This information is what is queried and used by Task Manager to populate the “Startup Impact” column.
About the author
Ramesh Srinivasan founded Winhelponline.com back in 2005. He is passionate about Microsoft technologies and has a vast experience in the ITeS industry — delivering support for Microsoft's consumer products. He has been a Microsoft MVP [2003 to 2012] who contributes to various Windows support forums.