Task-Specific Efficiency Analysis: When Small Language Models Outperform Large Language Models

arXiv cs.CL / 3/24/2026

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Key Points

  • The paper conducts a task-specific efficiency comparison of 16 language models across five NLP tasks, focusing on resource-constrained deployment trade-offs rather than only raw accuracy.
  • It introduces the Performance-Efficiency Ratio (PER), a metric that combines accuracy, throughput, memory, and latency via geometric mean normalization.
  • Results show that small language models in the 0.5B–3B parameter range outperform larger models on PER for all evaluated tasks.
  • The study provides quantitative guidance for production decisions, suggesting that teams can prioritize inference efficiency with small models when marginal accuracy improvements from larger models are not worth the computational cost.

Abstract

Large Language Models achieve remarkable performance but incur substantial computational costs unsuitable for resource-constrained deployments. This paper presents the first comprehensive task-specific efficiency analysis comparing 16 language models across five diverse NLP tasks. We introduce the Performance-Efficiency Ratio (PER), a novel metric integrating accuracy, throughput, memory, and latency through geometric mean normalization. Our systematic evaluation reveals that small models (0.5--3B parameters) achieve superior PER scores across all given tasks. These findings establish quantitative foundations for deploying small models in production environments prioritizing inference efficiency over marginal accuracy gains.