ROCKET: Rapid Optimization via Calibration-guided Knapsack Enhanced Truncation for Efficient Model Compression

TL;DR

ROCKET is a training-free model compression method that optimally allocates compression levels across layers using a knapsack formulation and employs a single-step sparse matrix factorization, achieving high compression with minimal performance loss.

Contribution

It introduces a novel, training-free compression approach combining knapsack-based layer-wise allocation and a single-step sparse factorization, outperforming existing methods.

Findings

Achieves 20-50% compression with minimal performance loss.

Retains over 90% of original performance at 30% compression without fine-tuning.

Light fine-tuning significantly recovers performance, matching original models.

Abstract

We present ROCKET, a training-free model compression method that achieves state-of-the-art performance in comparison with factorization, structured-sparsification and dynamic compression baselines. Operating under a global compression budget, ROCKET comprises two key innovations: First, it formulates layer-wise compression allocation as a multi-choice knapsack problem, selecting the optimal compression level for each layer to minimize total reconstruction error while adhering to a target model size. Second, it introduces a single-step sparse matrix factorization inspired by dictionary learning: using only a small calibration set, it sparsifies weight coefficients based on activation-weights sensitivity and then updates the dictionary in closed form via least squares bypassing iterative optimization, sparse coding, or backpropagation entirely. ROCKET consistently outperforms existing compression approaches across different model architectures at 20-50\% compression rates. Notably, it retains over 90\% of the original model's performance at 30\% compression without any fine-tuning. Moreover, when applying a light fine-tuning phase, recovery is substantially enhanced: for instance, compressing Qwen3-14B to an 8B-parameter model and healing it with just 30 million tokens yields performance nearly on par with the original Qwen3-8B. The code for ROCKET is at github.com/mts-ai/ROCKET/tree/main.