PyTorch Lightning - Is Trainer necessary to use multiple GPUs?
If I want to take advantage of PyTorch Lightning's ability to train using multiple GPUs, do I have to use their Trainer?

if you want to use all the Lightning features (even multi-GPU) such as loggers, metrics tracking, and checkpointing, then you would need to use Trainer. On the other hand, if you are fine with some limited functionality you can check out the recent LightningLite.
