Performance

• vLLM Optimization Techniques: Diagnosing GPU, CPU, Memory, and I/O Bottlenecks

  October 15, 2026 · 31 min · llm, vllm, gpu, profiling, performance

  What to measure when vLLM inference is slow, and which comparisons establish the cause. Using measured examples of synchronous D2H, PP receive ordering, small GEMVs, pinned RAM, and cold mmap reads, this article explains how to distinguish GPU, CPU, memory, and I/O bottlenecks from TTFT, ITL, and throughput.