What problem does it solve? Aligning LLMs with human preferences typically requires DPO or PPO setups that demand a separate reference model, extra GPU memory, and complex configuration. SimPO removes the reference model entirely while outperforming DPO, making preference alignment simpler and more compute-efficient. ## Core Features & Use Cases - Reference-Free Preference Training: Run SimPO training on chosen/rejected preference pairs with beta, gamma-beta ratio, and optional SFT regularization via YAML configs. - Ready-Made Workflows: Prebuilt configurations for Mistral 7B base, Llama 3 8B instruct, and reasoning-intensive math/code tasks with tuned learning rates. - In-Depth References: Detailed guides on loss functions (sigmoid vs hinge), hyperparameter selection by model size, and preference dataset preparation. - Use Case: Fine-tune Llama 3 8B Instruct on the UltraFeedback preference dataset with a single accelerate launch command and DeepSpeed ZeRO-3, without provisioning a reference model. ## Quick Start Train Mistral 7B on the UltraFeedback preference dataset using SimPO with the provided YAML config and DeepSpeed ZeRO-3 accelerate launch.