Chinchilla: Model/Data Ratios on a Budget

When compute is limited, should you buy a bigger model or feed it more data? Chinchilla gave a counterintuitive answer in 2022: at a fixed training budget, a 70B model trained on 1.4T tokens outperformed a 280B model trained on 300B tokens, using the same compute. That points to an approximate 1:20 parameter-to-token ratio in that setup. If you’re planning an LLM training run, this paper offers a practical way to think about model size, data volume, and where your next dollar creates more learning.

The Cost of RLHF: Why 1.3B Beat 175B

GPT-3 at 175B lost to InstructGPT at 1.3B. This was not a win for parameter count. It was a win for instruction following. But that gain comes with a tradeoff: when you push a model to stay closer to human preference, you may also narrow its performance on some public NLP tasks. This article breaks down how RLHF works through SFT, reward models, and PPO, then looks at the alignment tax and what it means when you have to choose between controllability and broader capability.

PRM vs. ORM in Complex Reasoning

The model got the answer right, but its reasoning path was full of logical gaps. That is a common pattern in LLM reasoning: outcome reward models only reward the final answer, so systems can learn to land on the right output without building a reliable path to get there. OpenAI’s 2023 research showed why process reward models matter, especially on harder tasks. With step-level feedback and 800,000 annotated steps in PRM800K, PRM improved performance on complex math benchmarks. The real question is not whether PRM is better in general, but when the added latency and infrastructure are worth the extra verifiability.