Flash-GRPO

Flash-GRPO: Efficient Alignment for Video Diffusion via One-Step Policy Optimization

arXiv:2605.15980v2 Announce Type: replace Abstract: Group Relative Policy Optimization has emerged as essential for aligning video diffusion models with human preferences, but faces a critical computational bottleneck: training a 14B parametered model typically demands hundreds of GPU days per experiment. Existing efficiency methods reduce costs through sliding window subsampling training timesteps, but fundamentally compromise optimization, exhibiting severe instability and failing to reach...