17 · Build evidence of engineering judgment

Deep systems understanding · Study map 83 of 85

Lab 3 · Decide whether to split prefill and decode

Suggested preparation: Lab 2 · Keep chats smooth during document bursts

Picture it

Imagine splitting a kitchen so that one team chops vegetables and another cooks them in a different building. This specialization might be brilliantly efficient for a massive banquet, but disastrously slow for a single bowl of soup. A sound design proves exactly when the cost of carrying ingredients across the street is finally justified by the speed of the chefs.

What to understand

  • KV-transfer accounting, pool ratios, placement, and load sweeps
  • Same hardware budget, same quality, same workload

Follow the references

  1. 1 · Paper

    Zhong et al. · DistServe ↗

    Read the evaluation assumptions and design a counterexample workload.

  2. 2 · Documentation

    NVIDIA · Dynamo ↗

    Use a supported disaggregated deployment recipe after checking hardware and connector requirements.

Make it concrete

Compare aggregated chunked serving with a disaggregated setup using equal GPUs. If hardware is unavailable, produce an explicitly labeled analytical model and a runnable experiment plan; do not invent measured speedups.

You understand it when…

At what workload does your preferred design change, and what measurement explains the crossover?

This is a study map. Follow the reference for the full explanation; use the question to test your mental model. Browse the reference shelf.