Solved by Vasiliy_Kuznetsov in post #2 
              
              
                hi @eleflea, check out https://github.com/pytorch/vision/blob/master/references/classification/train_quantization.py for one example.  One approach which has proven to work well is: 

start QAT training from a floating point pre-trained model and with observers and fake_quant enabled
after a couple …