Why OpenAI's o1 Is A Huge Deal | YC Decoded

TL;DR

OpenAI’s o1 Preview and o1 Mini are a new class of LLMs designed for reasoning, using reinforcement-learned chain-of-thought to break down complex math, coding, and science problems. They perform at PhD-student level on benchmarks but are not preferred for informal/creative tasks.

Key insights

• o1 uses a chain-of-thought process trained via large-scale reinforcement learning, generating its own synthetic chains of thought that are judged by a reward model and used for further fine-tuning.
• Unlike earlier models where users manually prompted “think step by step,” no amount of prompt engineering on GPT‑4o could match o1’s reasoning ability.
• o1’s accuracy scales with the amount of compute allowed for thinking at inference time; more thinking time yields more accurate responses.