[ue4] we have a external process in compute encoder in gputrace timeline

We captured GPU trace files using Xcode to analyze and optimize GPU performance. We found that in the compute encoder section, besides compute shader dispatch, there is an additional overhead labeled as ‘external process’. Double-clicking on the external process doesn’t produce any response, making it difficult to associate it with specific compute shaders.

We have made modifications to our pipeline ourselves. I just want to understand what this external process overhead represents, and whether there’s a way to determine which compute shader is causing it.

screen shot is in attachment. Thanks

重现步骤

Hi Hanshu,

When launching a 4.27+ template on iOS 18.5 from Xcode 16.4, we are not seeing this external process entry. Can you confirm versions/device on your end? We can only speculate that this entry represents a portion of the compute pipeline being used by an actual external process running on the device external to the UE application.

Best regards.