Solved by ptrblck in post #2 
              
              
                I get a transfer time of approx. 700ms for an output of [1, 64, 2048, 1536] on my laptop, which shouldn’t have the fastest GPU connection compared to a server or workstation using: 
x = torch.randn(1, 64, 2048, 1536, device='cuda')
nb_iters = 100

# warmup
for _ in range(10):
    y = x.cpu()

torch.…