TDA4VM: Emulation frame rate issue

Hi team,

Here's an issue from the customer may need your help:

Following the README to run custom-model-onnx.ipynb , then got the following performance metrics for resnet18v2:

[0] Indian elephant/Elephas maximus
[1] tusker
[2] African elephant/Loxodonta africana
[3] warthog
[4] water buffalo/water ox/Asiatic buffalo/Bubalus bubalis

Statistics : 
 Inferences Per Second   :    1.92 fps
 Inference Time Per Image :  521.45 ms  
 DDR BW Per Image        :    0.00 MB

The customer is wondering why "inferences per second" is less than 2fps. Is there any thing wrong? Or this item is not the exact frame rate on the board?
Could you help check this case? Thanks.
Best Regards,
Cherry