Work

CoopQ: Cooperative Game Inspired Layerwise Mixed Precision Quantization for LLMs

Year: 2026
Type: conference-paper
Abstract: Large Language Models (LLMs) promise impressive capabilities, yet their multi-billionparameter scale makes on-device or lowresource deployment prohibitive.Mixedprecision quantization offers a compelling solution, but existing methods struggle when the average precision drops below four bits, as they rely on isolated, layer-specific metrics that overlook critical inter-layer interactions affecting overall performance.To address these limitations, we first frame the mixed-precision quantization problem as a cooperative game among layers and introduce Shapley-based Progressive Quantization Estimation (SPQE) to efficiently obtain accurate Shapley estimates of layer sensitivities and inter-layer interactions.Leveraging the SPQE estimates, we propose Cooperative Game Inspired Mixed-Precision Quantization (CoopQ) which translates these Shapley estimates into a binary quadratic optimization formulation, assigning either 2 or 4-bit precision to layers under strict memory constraints.Comprehensive experiments conducted on Llama-3, Gemma-2, and Qwen-3 models across three independent PTQ backends (Quanto, HQQ, GPTQ) demonstrate CoopQ's scalability and consistently superior performance compared to methods relying solely on isolated metrics.Across average precisions spanning 4 bit down to 2 bit, CoopQ cuts Perplexity by 20 -80 % relative to the best baseline, with the margin growing as the bit-width tightens.
Language: English
Open Access status: hybrid
OpenAlex ID: W7166888950
FWCI: 8.828
Cites:
Cited by: 1
Related to: 10