[Solved] How to understand these empty columns in the report?


I am using Nsignt in Visual Studio 2015 for analyzing performance of a NVIDIA Optix application. The UI of the application is written in Python.

As you can see in the Timeline, there are completely empty columns between 2.6152 to 2.6163. I don’t understand what CUDA is doing right there, nor why it is empty. The last Driver API and Function Calls before the empty columns is cuEventElapsedTime

I have only One GPU, the ray-traced scene is simple and only device to device copy should occur for outputs.

Please help, thanks



With system tracing enabled, it is very clear that the empty part is called by the sleep code I made.