Brian Kearney

26 January 2026

27 new episodes (19 hours listening) published by the 38 podcasts on the list. 2 highlight clips below (4 mins total).

AI 26 January 2026 · 2 clips

Lex Fridman

Nathan Lambert and Sebastian Raschka

Nathan Lambert is post-training lead at the Allen Institute for AI (Ai2) and author of The RLHF Book; the episode draws on Ai2's own OLMo 3 runs, cluster invoices and contamination research. Sebastian Raschka wrote Build a Large Language Model (From Scratch) and Build a Reasoning Model (From Scratch), and reimplements published architectures from GPT-2 upward to check them.

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Lex Fridman

31 January 2026 · 4h 25m · 2 clips below

  1. 1 of 2 explainer

    The Allen Institute for AI spent about two million dollars renting the cluster that trained OLMo 3, a figure that makes building a model the cheap half of owning one.

    A thousand-GPU rental runs roughly 100,000 dollars a day, and hundreds of millions of users turn that into billions a year, which is why the largest models are rumoured to have shrunk back below a trillion parameters rather than grown. Labs hit the serving bill long before they hit any limit on whether bigger models keep working.

    1m 28s · from 52:10

  2. 2 of 2 contrarian

    Qwen's base model answers reworded maths problems with a precision that tool-free generation cannot produce, which two papers this year read as the benchmark having leaked into training.

    Keep the wording of a word problem and change only the numbers: a model that reasons degrades, while one that memorised near-identical items keeps returning answers to more decimal places than plain generation allows. Most published reinforcement-learning results are measured on that same benchmark and that same model family, so what reads as a capability gain may be recall.

    2m 10s · from 1:44:20

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