AI Accelerator Design · All levels

Performance-per-Watt Optimization Workflow: Reports and Metrics

Reports and Metrics for Performance-per-Watt Optimization Workflow.

Reports and metrics

Reports and Metrics for Performance-per-Watt Optimization Workflow is anchored on Sustained throughput per watt under SLA-constrained load, including memory and host-orchestration overhead.. Convert measurements into mechanism-backed decisions with clear owner accountability.

A useful report explains why movement happened, not only that movement happened.

Evidence matrix

diagram
EVIDENCE MATRIX - Performance-per-Watt Optimization Workflow

+-----------------------------+--------------------------------+--------------------------------+---------------------------+
| Evidence                    | Tells you                      | Does not prove                 | Next action               |
+-----------------------------+--------------------------------+--------------------------------+---------------------------+
| occupancy + timeline traces | where utilization is lost      | precise root cause             | map to memory and schedule|
| cache/SRAM/bandwidth stats  | data movement pressure         | model-level quality impact     | correlate with quality run|
| counter + profile alignment | bottleneck class confidence    | rollout safety                 | run full regression matrix|
| thermal/power telemetry     | sustained operating envelope   | correctness closure            | pair with verification    |
| before/after scenario pack  | mitigation movement            | long-tail stability            | execute guardrail replay  |
+-----------------------------+--------------------------------+--------------------------------+---------------------------+
  • Track Sustained throughput per watt under SLA-constrained load, including memory and host-orchestration overhead. on representative production workloads.

  • Include build/runtime metadata in every report header.

  • Correlate throughput, latency, and quality before rollout decisions.

  • Call out contradictory evidence explicitly.

AI accelerator deep dive

Precision and DVFS policy must be co-designed with quality guardrails and thermal behavior.

Concept diagram

diagram
PRECISION-POWER LOOP

numeric format choice -> throughput and energy
         + thermal state and DVFS policy -> sustained SLA

Metric graph

diagram
PERF/W TRADE

INT8 efficiency      █████████
BF16 stability       ██████
thermal clamp risk   ████

Metrics and artifacts to collect

  • precision-mode mix

  • perf-per-watt trend

  • thermal clamp frequency

  • quality regression monitor

Mini case study

Switching to lower precision improved nominal throughput, but thermal clamp cycles reduced sustained gains.

Debug branches

  • Validate quality guardrails by slice

  • Correlate thermal events to latency tails

  • Audit precision fallback behavior

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.

Report interpretation

Performance per watt improves when compute occupancy, memory locality, and scheduling policy are tuned as one system. Kernel fusion, tile-size alignment, and memory traffic shaping reduce wasted movement so each watt contributes to useful work. Runtime policies such as micro-batching, admission control, and stream prioritization can further lift efficiency if tail latency remains within target. The strongest gains come from iterative profiling loops that attribute energy to specific kernels, data paths, and idle intervals, then remove the dominant inefficiencies first. A useful explanation always ties observed symptom to a repeatable path where useful work was blocked, delayed, or diluted by overhead.

Use Sustained throughput per watt under SLA-constrained load, including memory and host-orchestration overhead. as an alarm, then anchor action using hard evidence such as Perf-per-watt optimization report with bottleneck ranking, intervention plan, and before-after operating points..

Precision policy is a system-level contract between quality, latency, and thermal limits. Senior reviews expect a chain of proof: workload intent -> mapping -> hardware behavior -> product impact.

For Performance-per-Watt Optimization Workflow, reports should explain why Sustained throughput per watt under SLA-constrained load, including memory and host-orchestration overhead. moved and which path consumed budget first.