Mixed-Precision Matmul: Throughput Gains with Accuracy Controls: Worked Example

Worked example

Worked Example for Mixed-Precision Matmul: Throughput Gains with Accuracy Controls is anchored on Tokens or inferences per second at fixed quality target and overflow or underflow incidence per training or inference step.. Convert measurements into mechanism-backed decisions with clear owner accountability.

A regression appears in Tokens or inferences per second at fixed quality target and overflow or underflow incidence per training or inference step.. Strong closure isolates first failing stage, proves mechanism, applies one reversible fix, and validates blast radius before release.

Execution lens

ACCELERATOR EXECUTION FLOW - Mixed-Precision Matmul: Throughput Gains with Accuracy Controls

request ingress and model metadata
      |
      v
graph lowering and kernel selection
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      v
tile/dataflow scheduling and memory placement
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      v
tensor execution + synchronization barriers
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      v
result assembly + quality/SLA validation
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      v
release decision and rollback guardrails

Decision matrix

EVIDENCE MATRIX - Mixed-Precision Matmul: Throughput Gains with Accuracy Controls

+-----------------------------+--------------------------------+--------------------------------+---------------------------+
| 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  |
+-----------------------------+--------------------------------+--------------------------------+---------------------------+

AI accelerator deep dive

Sparse and mixed-precision wins require stable compiler lowering and runtime support coverage.

Concept diagram

SPARSE TENSOR EXECUTION

model graph -> compiler lower -> sparse or dense kernel path -> runtime scheduling -> SLA outcome

Metric graph

SPARSE REALITY CHECK

nominal sparsity      ████████████
real speedup          ██████
fallback overhead     █████

Metrics and artifacts to collect

• tensor-core occupancy

• fallback kernel rate

• sparse metadata overhead

• quality guardrail drift

Mini case study

Structured sparsity improved one layer family while unsupported operators forced dense fallbacks elsewhere.

Debug branches

• Track dense fallback counters

• Audit sparse-format conversions

• Check precision policy with quality gates

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.

Worked-example reasoning

Suppose Tokens or inferences per second at fixed quality target and overflow or underflow incidence per training or inference step. regresses only under burst traffic. The shallow response is clock scaling. The stronger response is to inspect queueing, mapping, and memory-pressure interactions first.

If occupancy drops with high memory stalls, prioritize locality and scheduling fixes. If occupancy remains high with latency spikes, inspect contention and fairness policy.

Pick one bounded change per hypothesis and validate against baseline artifacts.