Full analysis
What happened, why it matters, the business impact, and what operators should watch next.
What happened
Amazon SageMaker Inference now offers prefix-aware routing, which sends requests sharing the same prompt prefix to the same instance so the KV cache stays warm. In benchmarks on Llama 3.1 70B, it reduced P50 time-to-first-token by up to 77% and increased KV cache hit rates from about 25% to over 80%.
Why it matters
The benchmark indicates that prefix-aware routing can improve latency and KV cache utilization for workloads with shared prompt prefixes.
Business impact
For applicable Llama 3.1 70B workloads, the benchmark indicates up to 77% lower P50 time-to-first-token and KV cache hit rates increasing from about 25% to over 80%.
Who is affected
Teams tracking Core AI, Infrastructure, product strategy, operations, and market positioning.
Operator take
Evaluate prefix-aware routing on Amazon SageMaker Inference for workloads with shared prompt prefixes. Treat the reported improvements as BENCHMARK results, confirmed as of 2026-09-10, rather than guaranteed production outcomes.