If the tensors are already on the GPU, then do you think it would be more optimal when creating the dictionary to make the keys on the GPU as well, or is easy just as easy to access it from cpu based keys? In my particular case I want to use keys that are generated from some mathematical manipulations of the tensors, so those keys would initially be on the GPU. My intuition is that the map itself does not live on the GPU, so it is not more optimal to have keys on the GPU, that need to be copied back to the CPU each time the dictionary is accessed. Hard to tell what’s really going on here.