DeepSpeed vs Megatron-LM: which stack fits pre-training, fine-tuning, and checkpoint portability?
Megatron-LM is the stronger research/pre-training substrate, while DeepSpeed is the broader optimization layer with more turnkey distributed features and integrations — but the real business cost difference is checkpoint portability and operational complexity, because Megatron Bridge and DeepSpeed↔Megatron integration reduce migration friction only if you standardize on compatible formats and workflows.