Time-to-First-Token Benefit of Long-Conversation Prefix Caching

Measure the time-to-first-token savings produced by capture-and-resume prefix caching for long multi-turn conversations on the distributed OpenVINO pipeline.

Background

Capture-and-resume prefix caching is designed to avoid re-prefilling a previously processed prompt prefix. The state is captured once per generation, making the state-query overhead potentially negligible compared with a full prefill.

The paper demonstrates correctness and describes the cache behavior, but it does not quantify the latency reduction for long conversations. The practical benefit of the method therefore remains unmeasured.

References

We have not yet measured the time-to-first-token savings on long conversations; so far the validation covers correctness, not the size of the latency win.

— Pre-Compiled Pipeline Shards for Distributed LLM Inference on Intel AI PC Fleets  (2608.19147 - Berenbaum et al., 19 Aug 2026) in Section 6.4, “Prefix Caching: KV Capture and Warm-Resume”