vix.ing · top · new · best · stats · spec

HA-RAG: Hotness-Aware RAG Acceleration via Mixed Precision and Data Placement

2025/10/23 by Ge, Danying, Gao, Jianhua, Yang, Yixue +1
#Artificial Intelligence (cs.AI) #C.4 #E.4 #FOS: Computer and information sciences #I.2 #Machine Learning (cs.LG)

paper · doi:10.48550/arxiv.2510.20878

Abstract

Retrieval-Augmented Generation (RAG) improves model output accuracy by leveraging external knowledge bases, serving as an effective solution to address hallucination issues and knowledge-update delays in Large Language Models (LLMs). However, the introduction of external knowledge bases presents RAG with challenges in long-context processing, significantly increasing memory consumption and inference latency. Existing research accelerates inference by precomputing Key and Value (KV) of the knowledge base and loading them on-demand during inference. Based on the access frequency of different KV chunks within the external knowledge base, this paper proposes a hotness-aware RAG (HA-RAG) inference optimization system. First, leveraging the numerical distribution of KV chunks, we introduce a hotness-aware mixed-precision compressing and loading method to reduce disk I/O and memory access overhead. Second, we design a hotness-aware data placement strategy that prioritizes storing frequently accessed KV chunks in high-speed memory to improve data access efficiency. Experimental results demonstrate that, compared with TurboRAG, the proposed HA-RAG achieves an average speedup of 2.10x and maximum speedup of 10.49x in Time-To-First-Token (TTFT) with negligible accuracy loss.

Citations

Related