arXiv Machine Learning

Why Does Adaptive Batching Help LLM Pretraining? A Perspective from Unbounded Variance

The paper investigates why increasing batch size during large language model pretraining helps, challenging the common assumption of bounded stochastic gradient variance. By introducing a generalized Blum–Gladyshev noise model that allows variance to grow with a tunable exponent, the authors derive theoretical bounds on oracle complexity and design an adaptive batch scheduler that adjusts batch size dynamically. Experiments on OLMo2 models up to 1B parameters show that this scheduler achieves lower validation loss than fixed small or large batch training while using fewer iterations.

arXiv Machine Learning
Sep 24

Linear RNN Scaling Laws: When Longer Sequences Beat More Sequences

The paper presents empirical scaling laws for autoregressive language models, linking prediction loss to model size, data size, and compute, and investigates their theoretical basis using a teacher–student linear RNN framework. In this tractable setting, a stable latent linear RNN generates trajectories while a sketched linear recurrent student is trained via full‑batch WSD gradient descent on next‑token prediction. The study derives explicit approximation, optimization, and statistical scaling laws that depend on the sketch dimension, number of trajectories, and trajectory length, revealing how different power‑law exponents for innovation and initialization covariances affect the rates and crossovers between regimes.

By Ziyan Chen, Zhongzhu Zhou, Peilin Liu, Ding-Xuan Zhou
arXiv AI
Jul 29

Bridging Compute- and Data-Optimal Pretraining

arXiv:2607. 25271v1 Announce Type: cross Abstract: Classical compute-optimal scaling laws assume an unbounded supply of fresh pretraining data, yet pretraining is increasingly entering a regime in which compute grows faster than the availability of high-quality data.

By Tian Qin, Kimia Hamidieh, David Alvarez-Melis
arXiv AI
Aug 25

How Should LLMs Consume High-Quality Data? Optimal Data Scheduling via Quality-Aware Functional Scaling Laws

The paper proposes a theoretical framework for scheduling high‑quality data in large language model training by extending functional scaling laws to account for time‑varying data quality. It identifies two regimes—noise‑limited and signal‑limited—where high‑quality data should be used differently, and introduces a Drop‑Stable‑Rampup training schedule that adjusts batch size at the quality transition. Experiments on 15B MoE and 600M dense models show significant accuracy gains over conventional decay schedules across multiple benchmarks.

By Zhitao Zhu, Xili Wang, Shizhe Wu, Jiawei Fu, Xiaoqing Liu
arXiv AI
Oct 1

How Does Local Landscape Geometry Evolve in Language Model Pre-Training?

The paper investigates how the local landscape geometry of language model pre‑training evolves, identifying two distinct phases. In Phase I, the landscape starts sharp, causing instability and loss plateaus at high learning rates, which explains the need for learning‑rate warmup and suggests longer warmups for larger peak rates. In Phase II, the geometry is governed by gradient noise scale, revealing a depth‑flatness trade‑off that motivates a dynamic batch‑size scheduler that starts small and grows later in training.

By Zhanpeng Zhou, Yuhan Sun, Bingrui Li, Jinbo Wang, Huaijin Wu, Lei Wu, Junchi Yan
arXiv AI
Jul 3

Adaptive Batch Sizes Using Non-Euclidean Gradient Noise Scales for Stochastic Sign and Spectral Descent

arXiv:2602. 03001v2 Announce Type: replace-cross Abstract: To maximize hardware utilization, modern machine learning systems typically employ large constant or manually tuned batch size schedules, relying on heuristics that are brittle and costly to tune.

By Hiroki Naganuma, Shagun Gupta, Youssef Briki, Ioannis Mitliagkas, Irina Rish, Parameswaran Raman, Hao-Jun Michael Shi