Running Out of Data.
Compute keeps growing; the internet does not grow as fast.
This volume describes the field as of October 2026. Claims are marked established (replicated or long-standing), reported (from a single lab or report, not independently reproduced) or contested (actively disputed). Villalobos and colleagues (ICML 2024) estimated the effective stock of public human-generated text at about 300 trillion tokens (90% interval 100 trillion to 1000 trillion) and projected that frontier training would use it up between 2026 and 2032 (reported estimate with wide uncertainty). Compute-optimal training (plate X.3) wants about 20 tokens per parameter, so data needed grows with the square root of compute — and frontier compute has been growing several-fold a year.
Muennighoff and colleagues found up to 4 epochs of repeated data nearly as good as fresh data (established for their settings), which stretches the stock. The workshop projects the tokens a compute-optimal frontier run would need, from Llama 3 405B’s 3.8 × 10²⁵ FLOPs in 2024, at the chosen compute growth per year, and finds when it exceeds the stock times the allowed repetition.
Below: tokens wanted by a compute-optimal frontier run each year against the usable stock; readouts give the crossing year.
- State the estimated stock of text.
- Relate data needed to compute.
- Project when they meet.
- List the responses and their status.
A wall that moves with assumptions
A compute-optimal run at Llama 3 405B’s 2024 compute wants about 11.3 trillion tokens. At four-fold compute growth a year, it outgrows a single pass over the central 300-trillion-token stock around 2033 and four passes around 2037. Every assumption moves the date by years — the stock’s uncertainty spans a factor of ten, growth rates vary, and frontier runs already train far past 20 tokens per parameter, which wants more data, not less. The direction is robust; the date is not.
The responses each have a status. Repetition is established up to a few epochs. Synthetic data is in heavy use and its ceiling is contested (previous plate). Multimodal data — video, audio — adds tokens of uncertain value for language (contested). Reinforcement learning extracts more from fewer tokens and has absorbed a growing share of compute (reported shift). And private data — licensed books, enterprise documents, user interactions — raises legal and consent questions (plate IX.9). The wall is less a cliff than a rising price per useful token.
Terms
- Data wall
- The point where wanted training tokens exceed usable human text.
- Stock of text
- The estimated quantity of usable public human-written text.
- Repetition
- Training several epochs over the same data.
- Compute-optimal tokens
- About 20 per parameter at the Chinchilla optimum.
Sources
- Villalobos et al., “Will we run out of data? Limits of LLM scaling based on human-generated data”, ICML 2024.
- Muennighoff et al., “Scaling Data-Constrained Language Models”, NeurIPS 2023.
- Hoffmann et al., “Training Compute-Optimal Large Language Models”, NeurIPS 2022.