RISC-V Design · All levels

Pipeline Performance and CPI Decomposition: Silicon PPA Impact

Silicon PPA Impact for Pipeline Performance and CPI Decomposition.

Silicon PPA impact

Silicon PPA Impact for Pipeline Performance and CPI Decomposition is anchored on Measured CPI broken into ideal base CPI, structural stalls, data stalls, control stalls, and memory wait contributions.. Convert observations into mechanism-backed decisions with explicit ownership.

  • Frequency gains that increase bubbles may lose net throughput.

  • Area growth from extension logic must justify workload value.

  • Power and thermal stability are release gates, not secondary metrics.

PPA trend view

diagram
BEFORE / AFTER TREND - Pipeline Performance and CPI Decomposition

Measured CPI broken into ideal base CPI, structural stalls, data stalls, control stalls, and memory wait contributions.
  ^
  |                           o target band
  |                    o after fix + reruns
  |             o
  |      o baseline (failing)
  +--------------------------------------------------> iteration
       capture issue      isolate mechanism      close + monitor

Use this view to confirm the gain is causal and stable across seeds.