Is the Trainer slower than customised loops?

Hmm, if you want to know more about the technical details of fine-tuning, I think it would be quicker to ask on Hugging Face Discord or Unsloth’s Discord…

Regarding the speed difference between Trainer and PyTorch Trainer, the opposite case can also occur. If you want to make effective use of multi-GPU with Trainer, I think you will need FSDP or DeepSpeed, so there may be some overhead there.