Minseok Seo;Jungi Hyun;Seongho Jeong;Xuan Truong Nguyen;Hyuk-Jae Lee;Hyokeun Lee
{"title":"OASIS: Outlier-Aware KV Cache Clustering for Scaling LLM Inference in CXL Memory Systems","authors":"Minseok Seo;Jungi Hyun;Seongho Jeong;Xuan Truong Nguyen;Hyuk-Jae Lee;Hyokeun Lee","doi":"10.1109/LCA.2025.3567844","DOIUrl":null,"url":null,"abstract":"The key-value (KV) cache in large language models (LLMs) now necessitates a substantial amount of memory capacity as its size proportionally grows with the context’s size. Recently, Compute-Express Link (CXL) memory becomes a promising method to secure memory capacity. However, CXL memory in a GPU-based LLM inference platform entails performance and scalability challenges due to the limited bandwidth of CXL memory. This paper proposes OASIS, an outlier-aware KV cache clustering for scaling LLM inference in CXL memory systems. Our method is based on the observation that clustering is effective in trading off between performance and accuracy compared to previous quantization- or selection-based approaches if clustering is aware of outliers. Our evaluation shows OASIS yields 3.6× speedup compared to the case without clustering while preserving accuracy with just 5% of full KV cache.","PeriodicalId":51248,"journal":{"name":"IEEE Computer Architecture Letters","volume":"24 1","pages":"165-168"},"PeriodicalIF":1.4000,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Computer Architecture Letters","FirstCategoryId":"94","ListUrlMain":"https://ieeexplore.ieee.org/document/10990150/","RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"COMPUTER SCIENCE, HARDWARE & ARCHITECTURE","Score":null,"Total":0}
引用次数: 0
Abstract
The key-value (KV) cache in large language models (LLMs) now necessitates a substantial amount of memory capacity as its size proportionally grows with the context’s size. Recently, Compute-Express Link (CXL) memory becomes a promising method to secure memory capacity. However, CXL memory in a GPU-based LLM inference platform entails performance and scalability challenges due to the limited bandwidth of CXL memory. This paper proposes OASIS, an outlier-aware KV cache clustering for scaling LLM inference in CXL memory systems. Our method is based on the observation that clustering is effective in trading off between performance and accuracy compared to previous quantization- or selection-based approaches if clustering is aware of outliers. Our evaluation shows OASIS yields 3.6× speedup compared to the case without clustering while preserving accuracy with just 5% of full KV cache.
期刊介绍:
IEEE Computer Architecture Letters is a rigorously peer-reviewed forum for publishing early, high-impact results in the areas of uni- and multiprocessor computer systems, computer architecture, microarchitecture, workload characterization, performance evaluation and simulation techniques, and power-aware computing. Submissions are welcomed on any topic in computer architecture, especially but not limited to: microprocessor and multiprocessor systems, microarchitecture and ILP processors, workload characterization, performance evaluation and simulation techniques, compiler-hardware and operating system-hardware interactions, interconnect architectures, memory and cache systems, power and thermal issues at the architecture level, I/O architectures and techniques, independent validation of previously published results, analysis of unsuccessful techniques, domain-specific processor architectures (e.g., embedded, graphics, network, etc.), real-time and high-availability architectures, reconfigurable systems.