KurTail : Kurtosis-based LLM Quantization
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Abstract (arXiv)
One of the challenges of quantizing a large language model (LLM) is the presence of outliers. Outliers often make uniform quantization schemes less effective, particularly in extreme cases such as 4-bit quantization. We introduce KurTail, a new post-training quantization (PTQ) scheme that leverages Kurtosis-based rotation to mitigate outliers in the activations of LLMs. Our method optimizes Kurtosis as a measure of tailedness. This approach enables the quantization of weights, activations, and the KV cache in 4 bits. We utilize layer-wise optimization, ensuring memory efficiency. KurTail outperforms existing quantization methods, offering a 13.3% boost in MMLU accuracy and a 15.5% drop in Wiki perplexity compared to QuaRot. It also outperforms SpinQuant with a 2.6% MMLU gain and reduces perplexity by 2.9%, all while reducing the training cost. For comparison, learning the rotation using SpinQuant for Llama3-70B requires at least four NVIDIA H100 80GB GPUs, whereas our method requires only a single GPU, making it a more accessible solution for consumer GPU.
Key facts. Cited by 12 papers in the map (data through 14 Oct 2026). Builds on 26 of its 43 references that are in the map. First posted on arXiv 3 Mar 2025.
Builds on
26 of 43 references.
References · 26
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14 more
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- 2023AWQ: Activation-aware Weight Quantization for LLM Compression and Accelerationcited by 1,298
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Built on by
Citing papers per year: 2025: 6; 2026: 6.
12 papers.
- 2025Block Rotation is All You Need for MXFP4 Quantizationcited by 20
- 2025ButterflyQuant: Ultra-low-bit LLM Quantization through Learnable Orthogonal Butterfly Transformscited by 10
- 2025Neural Network Quantization for Microcontrollers: A Comprehensive Survey of Methods, Platforms, and Applicationscited by 7
- 2025SINQ: Sinkhorn-Normalized Quantization for Calibration-Free Low-Precision LLM Weightscited by 6
- 2025Beyond Outliers: A Study of Optimizers Under Quantizationcited by 6
- 2025Bandwidth-Efficient Adaptive Mixture-of-Experts via Low-Rank Compensationcited by 3
- 2026OffQ: Taming Structured Outliers in LLM Quantization by Offsettingcited by 1
- 2026When Quantization Is Free: An int4 KV Cache That Outruns fp16 on Apple Siliconcited by 0
- 2026When Local Variance Optimality Is Not Enough: RoPE-Aligned Q/K Rotations for Dynamic 4-Bit Quantisationcited by 0
- 2026HBQ: Hierarchical Scaling Block Quantization with Hardware-Efficiency-Aware Design for Accurate LLM Inferencecited by 0
- 2026Quantization Error Is Spectrally Flat: A Single Random Probe Is a Calibrated, Data-Free Sensitivity Estimator, with Application to Budget-Targeted Mixed-Precision Quantizationcited by 0
- 2026ThinQuant: Scalable Rotation Learning for Weight and Activation Quantization of LLMscited by 0
- 2026ThinQuant: Scalable Rotation Learning for Weight and Activation Quantization of LLMs28 Sep 2026
- 2026Quantization Error Is Spectrally Flat: A Single Random Probe Is a Calibrated, Data-Free Sensitivity Estimator, with Application to Budget-Targeted Mixed-Precision Quantization27 Sep 2026
- 2026HBQ: Hierarchical Scaling Block Quantization with Hardware-Efficiency-Aware Design for Accurate LLM Inference31 Aug 2026
- 2026When Local Variance Optimality Is Not Enough: RoPE-Aligned Q/K Rotations for Dynamic 4-Bit Quantisation13 Aug 2026
- 2026OffQ: Taming Structured Outliers in LLM Quantization by Offsetting5 Jun 2026
- 2026When Quantization Is Free: An int4 KV Cache That Outruns fp16 on Apple Silicon7 May 2026
- 2025Bandwidth-Efficient Adaptive Mixture-of-Experts via Low-Rank Compensation18 Dec 2025
- 2025Block Rotation is All You Need for MXFP4 Quantization6 Nov 2025
- 2025Beyond Outliers: A Study of Optimizers Under Quantization27 Sep 2025
- 2025SINQ: Sinkhorn-Normalized Quantization for Calibration-Free Low-Precision LLM Weights26 Sep 2025
- 2025ButterflyQuant: Ultra-low-bit LLM Quantization through Learnable Orthogonal Butterfly Transforms11 Sep 2025
- 2025Neural Network Quantization for Microcontrollers: A Comprehensive Survey of Methods, Platforms, and Applications20 Aug 2025
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