FewStepRL: Fine-tuning Few-step Diffusion Models with Reinforcement Learning

A method called FewStepRL fine-tunes few-step diffusion models with reinforcement learning, targeting the rollout cost that dominates RL post-training for diffusion models, according to the research write-up. The work addresses the tradeoff that few-step models cut rollout cost but model an approximate distribution, and it is presented as a way to apply RL objectives without the many-step sampler rollouts that typically drive training expense. The approach matters for teams post-training diffusion models who want RL gains at lower sampling cost.

Reinforcement learning RL has become a standard post-training method for diffusion models, but most RL objectives roll out the current policy at every iteration, and with a many-step sampler these rollouts typically dominate the cost of training. Few-step models cut this cost, yet they model an av