To diagnose the CPU usage issues, you should use Event Tracing for Windows (ETW) to capture CPU Sampling data / Profile. To capture the data, install the Windows Performance Toolkit , which is part of the Windows SDK . The Windows 10 WPT can be used on Windows 8/Server 2012, Windows 8.1/Server 2012R2 and Windows 10/Server 2016. If you still use Windows 7, use the SDK/WPT with Build 15086 . (all other entries can be unselected) Now run WPRUI.exe , select First Level , under Resource select CPU usage and click on start . Now capture 1 minute of the CPU usage. After 1 minute, click on Save . Now analyze the generated ETL file with the Windows Performance Analyzer by dragging and dropping the CPU Usage (sampled) graph to the analysis pane and ordering the columns like you see in the picture: Inside WPA, load the debug symbols and expand Stack of the SYSTEM process. In this demo, the CPU usage comes from the nVIDIA driv...