If you want to manually send different payloads to the GPU each one you just had to do:
(tensorX or model).to(“cuda:0”)
(tensorX or model).to(“cuda:1”)
Then you manage each model manually on your code.
But if you prefer this information are done automatic, you just set your devide to  “cuda” this will use all your GPUs and wrap your model on DataParallel and the job will be split on the GPUs
device = “cuda”
model = MyModel()
model.to(device)
model = DataParallel(model)