SpecQuant: Speculative Decoding with Multi-Parent Quantization for Adaptive LLM Inference

Abstract:Running large language models (LLMs) locally continues to be limited by restrictions of compute and memory on consumer hardware. The popular acceleration technologies, such as quantization, speculative decoding, and adaptive inferencing, offer substantial speed boosts but usually necessitate retraining, per architecture tuning, or draft models. SpecQuant is a trainingfree framework, that combines speculative decoding with multiparent quantization to perform adaptive, efficient inference of LLMs. SpecQuant derives multiple quantized variants (INT4, FP8, FP16) from a shared base model, and dynamically routes queries based on predicted complexity; lightweight variants are used for simple or factual tasks, and full-precision models are used for complex reasoning tasks or long-context inputs. The shared-weight design of SpecQuant ensures sufficient token acceptance for speculative decoding without compatibility issues using separate draft parent models. We evaluate SpecQuant on Qwen2.5 based models on the MMLU, AlpacaEval, and GSM8K datasets, or benchmarks, demonstrating 35-43% speedups without degrading accuracy greater than 2%, substantial within the LLM community. SpecQuant enables practical on-device LLM deployment across diverse hardware without special infrastructure or expertise.

5 pages, 1 figure. Published in the 2026 Fifth International Conference on Power, Control and Computing Technologies (ICPC2T)

Machine Learning (cs.LG)

arXiv:2609.21704 [cs.LG]

(or arXiv:2609.21704v1 [cs.LG] for this version)

https://doi.org/10.48550/arXiv.2609.21704 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

2026 Fifth International Conference on Power, Control and Computing Technologies (ICPC2T), Raipur, India, 11-13 March 2026, pp. 371-375, IEEE, 2026

https://doi.org/10.1109/ICPC2T68221.2026.11646348 Focus to learn more DOI(s) linking to related resources

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