SPQ: An Ensemble Technique for Large Language Model Compression

Jiamin Yao, Eren Gultepe


Abstract
This study presents an ensemble technique, SPQ (SVD-Pruning-Quantization), for large language model (LLM) compression that combines variance-retained singular value decomposition (SVD), activation-based pruning, and post-training linear quantization. Each component targets a different source of inefficiency: i) pruning removes redundant neurons in MLP layers, ii) SVD reduces attention projections into compact low-rank factors, iii) and 8-bit quantization uniformly compresses all linear layers. At matched compression ratios, SPQ outperforms individual methods (SVD-only, pruning-only, or quantization-only) in perplexity, demonstrating the benefit of combining complementary techniques. Applied to LLaMA-2-7B, SPQ achieves up to 75% memory reduction while maintaining or improving perplexity (e.g., WikiText-2 reduced from 5.47 to 4.91) and preserving accuracy on downstream benchmarks such as C4, TruthfulQA, and GSM8K. Compared to strong baselines like GPTQ and SparseGPT, SPQ offers competitive perplexity and accuracy while using less memory (6.86 GB vs. 7.16 GB for GPTQ). Moreover, SPQ improves inference throughput over GPTQ, achieving up to a 1.9× speedup, which further enhances its practicality for real-world deployment. The effectiveness of SPQ’s robust compression through layer-aware and complementary compression techniques may provide practical deployment of LLMs in memory-constrained environments. Code is available at: https://github.com/JiaminYao/SPQ_LLM_Compression/
Anthology ID:
2026.lrec-1.489
Volume:
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
Stelios Piperidis, Núria Bel, Henk van den Heuvel, Nancy Ide, Simon Krek, Antonio Toral
Venue:
LREC
SIG:
Publisher:
ELRA Language Resource Association
Note:
Pages:
6185–6195
Language:
External URL:
https://lrec.elra.info/lrec2026-main-489
DOI:
10.63317/3t98siww4xf2
Bibkey:
Cite (ACL):
Jiamin Yao and Eren Gultepe. 2026. SPQ: An Ensemble Technique for Large Language Model Compression. In Proceedings of the Fifteenth Language Resources and Evaluation Conference, pages 6185–6195, Palma de Mallorca, Spain. ELRA Language Resource Association.
Cite (Informal):
SPQ: An Ensemble Technique for Large Language Model Compression (Yao & Gultepe, LREC 2026)
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