Skip prefill when the prefix is already warm.
Model the source loop with explicit assumptions: a cache hit restores stored KV state, so reusable prompt tokens do not need another prefill pass.
REQUEST → CHECK CACHE → HIT: LOAD KV → SKIP PREFILL → SERVE
ASSUMPTIONS READY
WORKLOAD RESULT
8,000,000baseline prefill tokens
5,600,000tokens avoided
$2.80prefill cost avoided
224.0 sprefill latency avoided
At 70% hits, 700 of 1,000 requests reuse the prefix instead of recomputing it.
Limitations: excludes cache warming, retrieval/transfer time, eviction, output decoding, and model-specific price changes.