Decouple Searching from Training: Scaling Data Mixing via Model Merging for Large Language Model Pre-training

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Li, Shengrui, Zhao, Fei, Zhao, Kaiyan, Ye, Jieying, Liu, Haifeng, Shi, Fangcheng, Xie, Zheyong, Hu, Yao, Cao, Shaosheng
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866918530794913792
author Li, Shengrui
Zhao, Fei
Zhao, Kaiyan
Ye, Jieying
Liu, Haifeng
Shi, Fangcheng
Xie, Zheyong
Hu, Yao
Cao, Shaosheng
author_facet Li, Shengrui
Zhao, Fei
Zhao, Kaiyan
Ye, Jieying
Liu, Haifeng
Shi, Fangcheng
Xie, Zheyong
Hu, Yao
Cao, Shaosheng
contents Determining an effective data mixture is a key factor in Large Language Model (LLM) pre-training, where models must balance general competence with proficiency on hard tasks such as math and code. However, identifying an optimal mixture remains an open challenge, as existing approaches either rely on unreliable tiny-scale proxy experiments or require prohibitively expensive large-scale exploration. To address this, we propose Decouple Searching from Training Mix (DeMix), a novel framework that leverages model merging to predict optimal data ratios. Instead of training proxy models for every sampled mixture, DeMix trains component models on candidate datasets at scale and derives data mixture proxies via weighted model merging. This paradigm decouples search from training costs, enabling evaluation of unlimited sampled mixtures without extra training burden and thus facilitating better mixture discovery through more search trials. Extensive experiments demonstrate that DeMix breaks the trade-off between sufficiency, accuracy and efficiency, obtaining the optimal mixture with higher benchmark performance at lower search cost. Additionally, we release the DeMix Corpora, a comprehensive 22T-token dataset comprising high-quality pre-training data with validated mixtures to facilitate open research. Our code and DeMix Corpora is available at https://github.com/Lucius-lsr/DeMix.
format Preprint
id arxiv_https___arxiv_org_abs_2602_00747
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Decouple Searching from Training: Scaling Data Mixing via Model Merging for Large Language Model Pre-training
Li, Shengrui
Zhao, Fei
Zhao, Kaiyan
Ye, Jieying
Liu, Haifeng
Shi, Fangcheng
Xie, Zheyong
Hu, Yao
Cao, Shaosheng
Computation and Language
Artificial Intelligence
68T50
I.2.7
Determining an effective data mixture is a key factor in Large Language Model (LLM) pre-training, where models must balance general competence with proficiency on hard tasks such as math and code. However, identifying an optimal mixture remains an open challenge, as existing approaches either rely on unreliable tiny-scale proxy experiments or require prohibitively expensive large-scale exploration. To address this, we propose Decouple Searching from Training Mix (DeMix), a novel framework that leverages model merging to predict optimal data ratios. Instead of training proxy models for every sampled mixture, DeMix trains component models on candidate datasets at scale and derives data mixture proxies via weighted model merging. This paradigm decouples search from training costs, enabling evaluation of unlimited sampled mixtures without extra training burden and thus facilitating better mixture discovery through more search trials. Extensive experiments demonstrate that DeMix breaks the trade-off between sufficiency, accuracy and efficiency, obtaining the optimal mixture with higher benchmark performance at lower search cost. Additionally, we release the DeMix Corpora, a comprehensive 22T-token dataset comprising high-quality pre-training data with validated mixtures to facilitate open research. Our code and DeMix Corpora is available at https://github.com/Lucius-lsr/DeMix.
title Decouple Searching from Training: Scaling Data Mixing via Model Merging for Large Language Model Pre-training
topic Computation and Language
Artificial Intelligence
68T50
I.2.7
url https://arxiv.org/abs/2602.00747