Oops, I checked cudnn version for pytorch via torch.backends.cudnn.version() and it returns 6021. Which means it uses cuDNN v6.
I don’t know what is the problem now…
According to following post, pytorch ships its own cuDNN version (6.0)

  
    
    
    Does Pytorch 0.2.0 still support cudnn 5.1 and how to manage different versions of cudnn? 
  
  
    Hi there, 
I have a question as shown in the title. 
First, does Pytorch 0.2.0 still support Cudnn 5.1? I have some Torch code to run, but currently Torch only support cudnn5.1, as far as I know. SO I install cudnn 5.1 globally in my CUDA installation folder. 
I then install pytorch using, 
conda install pytorch torchvision cuda80 -c soumith

But when I check within Pytorch cudnn version using, 
torch.backends.cudnn.version()

It shows cudnn version of 6021. But I do not have cudnn 6.0 installed…