ModelRefs / PagedAttention — AI Glossary

PagedAttention — AI Glossary

A KV-cache memory manager that allocates attention memory in non-contiguous pages, eliminating fragmentation and enabling high-throughput serving.

Overview

Introduced in vLLM. Enables 2–4× higher throughput on the same GPU by packing many concurrent sequences. Inspired by OS virtual memory paging. Now standard in vLLM, SGLang, and most production inference engines.

Reference details

Topicinference
Last reviewed2026-06-24

Commonly confused with

Easily confused with FlashAttention because both are named after attention and both raise throughput, but they fix different problems. PagedAttention manages KV-cache *memory*, allocating it in pages so it does not fragment and requests can share prefixes. FlashAttention changes how attention is *computed*. They are complementary and serving stacks generally use both at once.

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Frequently asked questions

What is PagedAttention?

A KV-cache memory manager that allocates attention memory in non-contiguous pages, eliminating fragmentation and enabling high-throughput serving.

What concepts are related to PagedAttention?

Closely related concepts include kv cache, vllm, throughput.