I saw this post involving @BramVanroy about setting CUDA_VISIBLE_DEVICES=0 to use just one of the 2 GPUs installed (I assume named 0 and 1). But is there any way to verify that only 1 GPU is being used when running the script? And I suppose even if so, doesn’t necessarily clarify how per_device_train_batch_size = 4 is being used when 2 GPUs are present, but I think (!) only one GPU being used.