arXiv Machine Learning

Layerwise Error Attribution for Fast and Robust Mixed-Precision Post-Training Quantization

Layerwise Error Attribution for Fast and Robust Mixed-Precision Post-Training Quantization proposes a new allocation method that assigns bits to layers under a global memory budget using a small calibration set. The method derives a layerwise probabilistic analysis separating propagated error from local perturbations, enabling a simple, solver‑free allocation algorithm that is robust to corrupted calibration data. Experiments on DRUNet denoising tasks and quantized diffusion models show significant speed‑ups (up to 2,570×) and improved performance, with PSNR gains of up to 7.5 dB under corrupted calibration.

arXiv AI
Jun 4

Model-Preserving Adaptive Rounding

arXiv:2505. 22988v3 Announce Type: replace-cross Abstract: The goal of quantization is to produce a compressed model whose output distribution is as close to the original model's as possible.

By Albert Tseng, Zhaofeng Sun, Christopher De Sa
arXiv AI
5d ago

When Lower Reconstruction Loss Hurts: Distributionally Robust Refinement for Low-Bit LLM Quantization

The paper examines weight-only post‑training quantization (PTQ) and finds that minimizing reconstruction loss does not always improve model performance, sometimes even harming it on calibration data. It shows that weights with low reconstruction loss on one distribution can perform worse when activation distributions shift. To address this, the authors introduce Distributionally Robust Quantization (DRQ), a refinement step that minimizes worst‑case reconstruction loss over a constrained set of activation distributions while keeping the quantization grid unchanged. Experiments demonstrate that DRQ improves models quantized by several PTQ methods across dense and mixture‑of‑experts large language models, offering better downstream performance without extra inference cost.

By Yanlong Zhao, Xiaoyuan Cheng, Huihang Liu, Baihua He, Xinyu Zhang, Harrison Bo Hua Zhu, Wenlong Chen, Li Zeng, Zhuo Sun
arXiv AI
Jun 4

Recover-LoRA for Aggressive Quantization: Reclaiming Accuracy in 2-Bit Language Models via Low-Rank Adaptation with Knowledge Distillation on Synthetic Data

arXiv:2606. 04238v1 Announce Type: cross Abstract: Aggressive weight quantization to 2-bit precision offers substantial throughput and memory gains for large language model (LLM) inference, but typically incurs severe accuracy degradation.

By Devleena Das, Rajeev Patwari, Elliott Delaye, Ashish Sirasao
arXiv AI
Aug 20

Entropy-Constrained Adaptive Stochastic Quantization

arXiv:2608. 18147v1 Announce Type: cross Abstract: Adaptive stochastic quantization (ASQ) is a recently introduced quantization approach that optimizes the Mean Squared Error (MSE) for a given input while preserving unbiasedness.

By Ran Ben Basat, Yaniv Ben-Itzhak, Michael Mitzenmacher, Shay Vargaftik