I followed your suggestion and fed random inputs to the model, but no luck. Just to make sure if I did this correctly: I removed the data loader altogether and just loaded a batch of random tensors, but this also did not increase my GPU usage. I still need to look at pyprof.
I noticed that changing the number workers from 0 to 16 does not seem to significantly change my CPU usage (I have 8 cores). That seems strange.
For the imagenet example it seems that I need to download the data, is that correct? I am waiting for approval. Do you by any chance have another example to check both mixed precision and data loading bottlenecks? Any ideas are appreciated! Thanks