What causes large latency jitters when SGIEs are added?

Accelerated Computing Intelligent Video Analytics DeepStream SDK
1

Please provide complete information as applicable to your setup.

• Hardware Platform (Jetson / GPU): Jetson AGX Xavier
• DeepStream Version: 5.0
• JetPack Version (valid for Jetson only): 4.4
• TensorRT Version: 7.1
• Issue Type( questions, new requirements, bugs): questions

I have the following pipeline:

camera-1  
        \
         ---> muxer -> pgie -> tracker -> sgie1 -> sgie2 -> app_sink 
        /
camera-2

The app_sink call a function that trigger external hardware based on the result of of sgie1 & sgie2 on detected object. We measure the latency from the time the images were captured at the camera to the time the external hardware receive the instruction.

When sgie1 & sgie2 are included, the latency range from 68ms to 80ms, however, when we removed sgie1 & sgie2 the latency does not change as much and range from 50-53ms. What could be the cause of large latency jitters when SGIEs are added?

3

Hi,
Can you set CPU/GPU/EMC clock to constant, like to max,
sudo nvpmodel -m 0
sudo jetson_clocks
and try again?

4

It’s expected since the sgie perform inference on the result from pgie, that means if the pgie detect more objects, then sgie will consume more time to do inference.

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