On the Importance of a Multi-Scale Calibration for Quantization

Fuente: arXiv
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Main Authors: Son, Seungwoo, Seong, Ingyu, Kim, Junhan, Jang, Hyemi, Jeon, Yongkweon
Format: Preprint
Published: 2026
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author Son, Seungwoo
Seong, Ingyu
Kim, Junhan
Jang, Hyemi
Jeon, Yongkweon
author_facet Son, Seungwoo
Seong, Ingyu
Kim, Junhan
Jang, Hyemi
Jeon, Yongkweon
contents Post-training quantization (PTQ) is a cornerstone for efficiently deploying large language models (LLMs), where a small calibration set critically affects quantization performance. However, conventional practices rely on random sequences of fixed length, overlooking the variable-length nature of LLM inputs. Input length directly influences the activation distribution and, consequently, the weight importance captured by the Hessian, which in turn affects quantization outcomes. As a result, Hessian estimates derived from fixed-length calibration may fail to represent the true importance of weights across diverse input scenarios. We propose MaCa (Matryoshka Calibration), a simple yet effective method for length-aware Hessian construction. MaCa (i) incorporates multi-scale sequence length information into Hessian estimation and (ii) regularizes each sequence as an independent sample, yielding a more stable and fruitful Hessian for accurate quantization. Experiments on state-of-the-art LLMs (e.g., Qwen3, Gemma3, LLaMA3) demonstrate that MaCa consistently improves accuracy under low bit quantization, offering a lightweight enhancement compatible with existing PTQ frameworks. To the best of our knowledge, this is the first work to systematically highlight the role of multi-scale calibration in LLM quantization.
format Preprint
id arxiv_https___arxiv_org_abs_2602_07465
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle On the Importance of a Multi-Scale Calibration for Quantization
Son, Seungwoo
Seong, Ingyu
Kim, Junhan
Jang, Hyemi
Jeon, Yongkweon
Machine Learning
Computation and Language
Post-training quantization (PTQ) is a cornerstone for efficiently deploying large language models (LLMs), where a small calibration set critically affects quantization performance. However, conventional practices rely on random sequences of fixed length, overlooking the variable-length nature of LLM inputs. Input length directly influences the activation distribution and, consequently, the weight importance captured by the Hessian, which in turn affects quantization outcomes. As a result, Hessian estimates derived from fixed-length calibration may fail to represent the true importance of weights across diverse input scenarios. We propose MaCa (Matryoshka Calibration), a simple yet effective method for length-aware Hessian construction. MaCa (i) incorporates multi-scale sequence length information into Hessian estimation and (ii) regularizes each sequence as an independent sample, yielding a more stable and fruitful Hessian for accurate quantization. Experiments on state-of-the-art LLMs (e.g., Qwen3, Gemma3, LLaMA3) demonstrate that MaCa consistently improves accuracy under low bit quantization, offering a lightweight enhancement compatible with existing PTQ frameworks. To the best of our knowledge, this is the first work to systematically highlight the role of multi-scale calibration in LLM quantization.
title On the Importance of a Multi-Scale Calibration for Quantization
topic Machine Learning
Computation and Language
url https://arxiv.org/abs/2602.07465