arXiv Machine Learning
Oct 3

ConQuR: Corner Aligned Activation Quantization via Optimized Rotations for LLMs

ConQuR introduces a lightweight post‑training rotation calibration for large language model activation quantization. By learning orthogonal rotations that align normalized activations with the corners of an inscribed hypercube, the method distributes activation energy evenly and can be updated online without storing activations. Experiments on Llama‑2 and Llama‑3 models (3B–70B) show competitive or improved perplexity and reasoning performance while avoiding costly training or large offline storage.

By Chayne Thrash, Ali Abbasi, Soheil Kolouri
arXiv Machine Learning
Oct 15

PrismQuant: Optimal Null-Space Rotations for Grouped Quantizers

PrismQuant introduces a rotation framework that aligns the leading activation eigenspace with the constant group subspace of asymmetric grouped INT4 quantizers, optimizing the alignment via Ky Fan trace maximization and providing a closed‑form solution. The method employs compact Householder transformations for efficient, gradient‑free construction and applies a predictive range law to relate unaligned activation energy and group size to quantization variation. Experiments on large language models up to 70B parameters show PrismQuant achieving state‑of‑the‑art perplexity and accuracy, while delivering significant speedups and memory reductions in deployment scenarios.

By Yanlong Chen, Yining Chen, Song Zhang, Amirhossein Habibian, Yawei Li
arXiv AI
Sep 30

ThinQuant: Scalable Rotation Learning for Weight and Activation Quantization of LLMs

ThinQuant introduces efficient rotation learning for low‑bit weight and activation quantization of large language models by reducing calibration data through a geometric selection of activations and solving a lower‑dimensional optimization problem via an ADMM algorithm. The method achieves comparable or better quantization performance with dramatically fewer calibration points, completing rotation calibration for Llama‑3‑70B in under 12 minutes and for Llama‑3.1‑405B in just over 2 hours on a single GPU. ThinQuant outperforms existing gradient‑free approaches such as DartQuant and gradient‑based SpinQuant in both speed and perplexity metrics on WikiText‑2.

By Mehdi Makni, Ryan Lucas, Rahul Mazumder
arXiv Machine Learning
Oct 22

InfoQuant: Shaping Activation Distributions for Low-Bit LLM Quantization

InfoQuant is a train‑free method that reshapes activation distributions to be more compatible with low‑bit quantizers. It uses Peak Suppression Orthogonal Transformation (PSOT) and adaptive outlier‑token selection to reduce numerical range while maintaining dispersion, thereby lowering quantization error. Across several large language model families, InfoQuant outperforms existing post‑training quantization and end‑to‑end training baselines, preserving 97% of floating‑point accuracy on average and narrowing the LLaMA‑2 13B performance gap by 42%.

By Ke Li, Dong An, Xiaoling Zang, Can Ye, Liang Xie, Qibo Qiu, Chen Shen, Xiaofei He, Wenxiao Wang