perf-nsight-compute-analysis

Classify SOL% bottlenecks and diagnose CUDA kernel underperformance from Nsight Compute output.

Updated May 23, 2026
One-click install
npx skills add https://github.com/yo-steven/skills-exploration-20260522 --skill perf-nsight-compute-analysis-yo-steven
Or copy as Structured Prompt for Agent
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Skill: perf-nsight-compute-analysis
Source: https://github.com/yo-steven/skills-exploration-20260522/tree/main/skills/TensorRT-LLM/perf-nsight-compute-analysis
Command: npx skills add https://github.com/yo-steven/skills-exploration-20260522 --skill perf-nsight-compute-analysis-yo-steven

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill helps you interpret NVIDIA Nsight Compute (ncu) profiling results to identify why CUDA kernels are slow by using SOL% bottleneck classification and targeted analysis.

Core Features & Use Cases

  • SOL% bottleneck classification: Determine compute-bound vs memory-bound vs latency-bound using Speed of Light (SOL%) throughput signals.
  • Section-first profiling workflow: Guides you to collect only the necessary --section data (e.g., SpeedOfLight, Occupancy, Warp/Instruction stats) instead of exhaustive profiling.
  • Roofline + occupancy + stall diagnosis: Use roofline charts for compute/memory balance and occupancy/stall-related sections for latency and underutilization causes.
  • .ncu-rep programmatic report analysis: Provides an approach to extract and classify metrics from saved report files using the ncu_report Python API.

Quick Start

Run ncu with the SpeedOfLight section to classify the kernel bottleneck and decide which deeper sections to collect next.

Frequently Asked Questions about perf-nsight-compute-analysis

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I identify GPU bottlenecks using SOL% from Nsight Compute?

To diagnose CUDA kernel underperformance, analyze Nsight Compute SOL% metrics to classify bottlenecks as compute-bound, memory-bound, or latency-bound. Use targeted ncu profiling sections like SpeedOfLight, Occupancy, and Warp/Instruction stats to guide root-cause investigation of GPU kernel issues.

What is the best way to profile CUDA kernel occupancy and warp stalls with ncu?

Run ncu with targeted section flags like Occupancy and Warp/Instruction stats to investigate latency and underutilization causes. This section-first workflow avoids exhaustive profiling, focusing only on necessary data to interpret warp stalls and instruction issues efficiently.

Can I extract metrics from a saved .ncu-rep file programmatically?

Yes, you can extract and classify metrics from saved .ncu-rep files using the ncu_report Python API. This approach enables programmatic analysis of Nsight Compute reports to classify SOL% bottlenecks and diagnose kernel performance issues.

Does Nsight Compute roofline analysis help find memory vs compute bottlenecks?

Yes, roofline analysis charts compute-memory balance to classify SOL% bottlenecks. Combined with occupancy and stall-related sections, it visually confirms whether your CUDA kernel is compute-bound or memory-bound, guiding deeper latency root-cause investigation.

What are the limitations of using SOL% analysis for GPU profiling?

SOL% analysis is limited to kernel-level performance diagnosis and does not support nsys system profiling or kernel code generation. It requires running ncu with targeted section flags and focuses strictly on SOL% compute-versus-memory classification, occupancy, and warp stall interpretation.