Synthetic data cuts loss on real distribution and yields 1.8x data efficiency in constrained pretraining

AndrewLampinen · x · 2026-10-14

Cited by Andrew Lampinen, konwookim's work shows that for data-constrained pretraining, synthetic data isn't just benchmark gaming: as more tokens are generated, loss on the real data distribution actually drops. A further scaling trick — treating synthetic generations as one long "megadoc" — yields 1.8x data efficiency, with larger gains as compute increases.

Related event: New Research Suggests Cumulative Synthetic Data Won't Collapse Models(4 posts)→

Original post →

More from Research

Research channel →