Building a From‑Scratch LLM Training Framework: Full GRPO vs PPO vs DPO Comparison on GSM8K
The article presents a from‑scratch LLM training framework called grpo‑llm, implements GRPO with Trio rollout, FSDP and a C++ reward extension, and conducts a controlled experiment comparing GRPO, PPO and DPO on the GSM8K math‑reasoning benchmark, revealing why DPO outperforms the other two under sparse binary rewards.
