AI Accelerator Design · All levels

Batch Size Effects: Inputs and Outputs

Inputs and Outputs for Batch Size Effects.

Inputs and outputs contract

Inputs and Outputs for Batch Size Effects is anchored on Throughput, P99 latency, and energy per inference across batch sweep under target traffic patterns.. Convert measurements into mechanism-backed decisions with clear owner accountability.

diagram
INPUTS
  - workload profile and SLA target
  - model precision and quality thresholds
  - compiler/runtime/firmware metadata
  - hardware operating envelope assumptions

OUTPUTS
  - evidence-backed bottleneck classification
  - owner-signed mitigation proposal
  - validation matrix with rollback triggers
  - release recommendation

Ownership split

diagram
OWNERSHIP LAYERS - Batch Size Effects

+----------------------+--------------------------------+--------------------------------+
| Team                 | Primary responsibility         | Closure artifact               |
+----------------------+--------------------------------+--------------------------------+
| inference platform owner | mechanism and architecture intent| design rationale + tradeoffs   |
| capacity planning engineer | mapping, runtime, and execution   | profile traces + bottleneck map|
| SRE performance owner | correctness, risk, and signoff    | test report + closure memo     |
+----------------------+--------------------------------+--------------------------------+

AI accelerator deep dive

Scheduling quality decides whether architecture headroom reaches product throughput.

Concept diagram

diagram
SCHEDULING PIPELINE

compile plan -> runtime queue -> core placement -> completion and tail behavior

Metric graph

diagram
TAIL-LATENCY DRIVERS

queueing delay      ███████
core imbalance      █████
mapping fallback    ████

Metrics and artifacts to collect

  • queue wait profile

  • batch policy impact

  • core-level fairness

  • operator fusion effect

Mini case study

Aggressive fusion reduced launch overhead but increased memory bursts that worsened p95 latency.

Debug branches

  • Inspect tail first, not average

  • Check fairness across streams

  • Validate fusion against memory constraints

Senior review question

Ask: which first-principles bottleneck class explains the symptom, and what artifact proves it reproducibly?

Key takeaways

  • Tie every accelerator claim to a reproducible workload slice and one primary metric trend.

  • Prefer bounded fixes with clear owner and rollback boundary over broad tuning bundles.

Common pitfalls

  • Optimizing synthetic kernels without production-shape validation.

  • Reading average latency while ignoring p95 and p99 behavior.

  • Declaring sparse or precision wins without fallback and quality evidence.

Handoff explanation

Inputs should include workload profile, model revision, compiler/runtime versions, and platform power mode.

Outputs must include actionable interpretation of Throughput, P99 latency, and energy per inference across batch sweep under target traffic patterns., required artifacts (Batch policy curve pack showing feasible operating regions for throughput, latency, and power.), owner, and validation scope.

The ideal handoff packet is reproducible: fixed seeds, explicit baseline, and rejected alternatives.