Skip to content
“How Well Does RL Scale?” by Toby_Ord episode artwork

Oct 30, 2025 16 min

“How Well Does RL Scale?” by Toby_Ord

from LessWrong (Curated & Popular)

This is the latest in a series of essays on AI Scaling. You can find the others on my site. Summary: RL-training for LLMs scales surprisingly poorly. Most of its gains are from allowing LLMs to productively use longer chains of thought, allowing them to think longer about a problem. There is some improvement for a fixed length of answer, but not enough to drive AI progress. Given the scaling up of pre-training compute also stalled, we'll see less AI progress via compute scaling than you might have thought, and more of it will come from inference scaling (which has different effects on the world). That lengthens timelines and affects strategies for AI governance and safety. The current era of improving AI capabilities using reinforcement learning (from verifiable rewards) involves two key types of scaling: Scaling the amount of compute used for RL during training Scaling [...] --- Outline: (09:46) How do these compare to pre-training scaling? (14:16) Conclusion --- First published: October 22nd, 2025 Source: https://www.lesswrong.com/posts/xpj6KhDM9bJybdnEe/how-well-does-rl-scale --- Narrated by TYPE III AUDIO. --- Images from the article:

Episode details come from the podcast's RSS feed.

Embed this episode

This is the latest in a series of essays on AI Scaling. You can find the others on my site. Summary: RL-training for LLMs scales surprisingly poorly. Most of its gains are from allowing LLMs to productively use longer chains of thought, allowing them to think longer about a problem. There is some improvement for a fixed length of answer, but not enough to drive AI progress. Given the scaling up of pre-training compute also stalled, we'll see less AI progress via compute scaling than you ...

Ready to play

“How Well Does RL Scale?” by Toby_Ord

0:00 16:11

No transcript yet.

Requests help us decide what to transcribe next.

Frequently asked questions

How long is this episode of LessWrong (Curated & Popular)?

This episode is 16 minutes long.

When was this LessWrong (Curated & Popular) episode published?

This episode was published on October 30, 2025.

Can I download this LessWrong (Curated & Popular) episode?

Yes. Use the download control on the episode player to save the publisher-provided media file.