Prefill and Decode for Concurrent Requests - Optimizing LLM Performance

Explains the two stages of token generation for LLMs—prefill, where input tokens are processed in parallel to produce the first token, and decode, where subsequent tokens are generated sequentially using a KV cache. It defines latency metrics (time to first token and time per output token) and analyzes how concurrent requests and batching affect throughput on multi-GPU setups. It also hints at batching patterns like prefill-first and chunked prefill to optimize latency.

Source

HuggingFace Blog

Ingested

APR 16, 2025 · 19:10

Editorial score

4.0 / 5