TFlite conversion is slow on raspi4

Hi, I have converted my model for a computer vision application to be deployed onto a raspberry pi 4 4GB. I have converted it from PyTorch into a tflite format. Model works but its slower than running it in an onnx format via raspi.
Any way to improve the speed. I believe it’s supposed to be faster

onnx: 1 fps, 25 mb
tflite: 0.5 fps, 6mb