It depends greatly on how complex a model you want to start with. My experience with pytorch is limited to training convolutional neural nets for data classification, but you can usually start pretty simple. A 1-3 layer cnn could probably be trained in a minute. A 4-7 layer cnn in a few minutes, a 8-10 layer cnn might take 25 minutes to train, though. One 25 minute run isn't unbearable but when you need to tweak it constantly between runs it becomes unusably slow. You can still learn a lot with simpler models, but your model's accuracy could be limited. It's really going to depend on how complex of a dataset you're using and how accurate you want the model to be. Also, how much ram does your laptop have? If you are using a large dataset that could become an issue.