Qronos: Correcting the Past by Shaping the Future... in Post-Training Quantization

Fuente: arXiv
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Main Authors: Zhang, Shihao, Zhang, Haoyu, Colbert, Ian, Saab, Rayan
Format: Preprint
Published: 2025
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author Zhang, Shihao
Zhang, Haoyu
Colbert, Ian
Saab, Rayan
author_facet Zhang, Shihao
Zhang, Haoyu
Colbert, Ian
Saab, Rayan
contents We introduce Qronos -- a new state-of-the-art post-training quantization algorithm that sequentially rounds and updates neural network weights. Qronos not only explicitly corrects errors due to both weight and activation quantization, but also errors resulting from quantizing previous layers. Our iterative algorithm is based on an interpretable and disciplined optimization framework that subsumes and surpasses existing data-driven approaches. At each step, Qronos alternates between error correction and diffusion via optimal update rules. Importantly, we prove that Qronos admits an efficient implementation that uses the Cholesky decomposition for solving least-squares problems. We also demonstrate that Qronos is compatible with existing transformation techniques such as Hadamard-based incoherence processing and weight-activation scaling equalization, among others. We evaluate Qronos using recent autoregressive language generation models in the Llama3 family; Qronos consistently outperforms previous state-of-the-art adaptive rounding methods when quantizing the weights, activations, and/or KV caches.
format Preprint
id arxiv_https___arxiv_org_abs_2505_11695
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Qronos: Correcting the Past by Shaping the Future... in Post-Training Quantization
Zhang, Shihao
Zhang, Haoyu
Colbert, Ian
Saab, Rayan
Machine Learning
Artificial Intelligence
Optimization and Control
We introduce Qronos -- a new state-of-the-art post-training quantization algorithm that sequentially rounds and updates neural network weights. Qronos not only explicitly corrects errors due to both weight and activation quantization, but also errors resulting from quantizing previous layers. Our iterative algorithm is based on an interpretable and disciplined optimization framework that subsumes and surpasses existing data-driven approaches. At each step, Qronos alternates between error correction and diffusion via optimal update rules. Importantly, we prove that Qronos admits an efficient implementation that uses the Cholesky decomposition for solving least-squares problems. We also demonstrate that Qronos is compatible with existing transformation techniques such as Hadamard-based incoherence processing and weight-activation scaling equalization, among others. We evaluate Qronos using recent autoregressive language generation models in the Llama3 family; Qronos consistently outperforms previous state-of-the-art adaptive rounding methods when quantizing the weights, activations, and/or KV caches.
title Qronos: Correcting the Past by Shaping the Future... in Post-Training Quantization
topic Machine Learning
Artificial Intelligence
Optimization and Control
url https://arxiv.org/abs/2505.11695