M-ANT: Efficient Low-bit Group Quantization for LLMs via Mathematically Adaptive Numerical Type

Fuente: arXiv
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Main Authors: Hu, Weiming, Zhang, Haoyan, Guo, Cong, Feng, Yu, Guan, Renyang, Hua, Zhendong, Liu, Zihan, Guan, Yue, Guo, Minyi, Leng, Jingwen
Format: Preprint
Published: 2025
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author Hu, Weiming
Zhang, Haoyan
Guo, Cong
Feng, Yu
Guan, Renyang
Hua, Zhendong
Liu, Zihan
Guan, Yue
Guo, Minyi
Leng, Jingwen
author_facet Hu, Weiming
Zhang, Haoyan
Guo, Cong
Feng, Yu
Guan, Renyang
Hua, Zhendong
Liu, Zihan
Guan, Yue
Guo, Minyi
Leng, Jingwen
contents Large language models (LLMs) are one of the most important killer computer applications. The recent algorithmic advancement proposes a fine-grained group-wise quantization for LLMs, which treats a small set (e.g., 64) of values in a tensor as a compression unit. It effectively preserves the model accuracy without retraining, and has become the standard approach to efficiently deploy LLMs. On the other hand, there are works that propose various adaptive data types to better adapt to different distributions and further reduce the required bit length for LLMs. In this work, our detailed analysis unveils a key finding that while different tensors exhibit similar distributions, small groups can have markedly different distributions. As such, the group-level diversity requires a new level of adaptivity for which existing adaptive data types fail to provide. In this paper, we propose MANT, a mathematically adaptive numeric type, featuring a more flexible encoding paradigm with a wider range of data distribution and more efficient decodingcomputation fusion mechanism to address these challenges. Based on MANT, we develop a supporting framework to assign the appropriate data type for each group adaptively. Meanwhile, the dynamically generated Key-Value (KV) caches in LLMs introduce further complexity for real-time quantization. To tackle this, we propose an efficient real-time quantization mechanism. Besides, we implement a specific processing element (PE) to efficiently support MANT and incorporate a real-time quantization unit. By integrating these components into a systolic array, MANT unifies the group-wise weight and KV cache quantization and addresses the associated challenges. Our evaluation shows achieving, on average, 2.99x (up to 4.46x) speedup and 2.81x (up to 4.10x) energy reduction to the state-of-the-art LLM accelerator.
format Preprint
id arxiv_https___arxiv_org_abs_2502_18755
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle M-ANT: Efficient Low-bit Group Quantization for LLMs via Mathematically Adaptive Numerical Type
Hu, Weiming
Zhang, Haoyan
Guo, Cong
Feng, Yu
Guan, Renyang
Hua, Zhendong
Liu, Zihan
Guan, Yue
Guo, Minyi
Leng, Jingwen
Hardware Architecture
Large language models (LLMs) are one of the most important killer computer applications. The recent algorithmic advancement proposes a fine-grained group-wise quantization for LLMs, which treats a small set (e.g., 64) of values in a tensor as a compression unit. It effectively preserves the model accuracy without retraining, and has become the standard approach to efficiently deploy LLMs. On the other hand, there are works that propose various adaptive data types to better adapt to different distributions and further reduce the required bit length for LLMs. In this work, our detailed analysis unveils a key finding that while different tensors exhibit similar distributions, small groups can have markedly different distributions. As such, the group-level diversity requires a new level of adaptivity for which existing adaptive data types fail to provide. In this paper, we propose MANT, a mathematically adaptive numeric type, featuring a more flexible encoding paradigm with a wider range of data distribution and more efficient decodingcomputation fusion mechanism to address these challenges. Based on MANT, we develop a supporting framework to assign the appropriate data type for each group adaptively. Meanwhile, the dynamically generated Key-Value (KV) caches in LLMs introduce further complexity for real-time quantization. To tackle this, we propose an efficient real-time quantization mechanism. Besides, we implement a specific processing element (PE) to efficiently support MANT and incorporate a real-time quantization unit. By integrating these components into a systolic array, MANT unifies the group-wise weight and KV cache quantization and addresses the associated challenges. Our evaluation shows achieving, on average, 2.99x (up to 4.46x) speedup and 2.81x (up to 4.10x) energy reduction to the state-of-the-art LLM accelerator.
title M-ANT: Efficient Low-bit Group Quantization for LLMs via Mathematically Adaptive Numerical Type
topic Hardware Architecture
url https://arxiv.org/abs/2502.18755