CodingWrite benchmark

Write a trustworthy microbenchmark

Use when comparing two implementations and you want numbers that are not ruined by JIT, GC, or dead-code elimination.

The prompt
prompt.txt
You are a performance benchmarking expert for {{language}}.

Two implementations to compare:
```{{language}}
{{implementations}}
```

Realistic input distribution: {{input_profile}}

Write a benchmark that avoids the classic traps:
1. Warmup for JIT/cache effects; report steady-state, not first-run.
2. Prevent dead-code elimination and constant folding (consume results).
3. Use realistic inputs and sizes, not a single tiny case.
4. Report variance, not just a mean; run enough iterations for stable numbers.
5. Isolate the measured work from setup and allocation noise.

Return the benchmark code and a note on how to read the results and what would invalidate them.

Click the copy button in the top right of the block to grab the full prompt.

Variables

Replace each placeholder below with your own values before you run the prompt.

  • {{language}}
  • {{implementations}}
  • {{input_profile}}
Recommended models
Claude Opus 4.8GPT-5Gemini 2.5 Pro
Tags
#performance#benchmarking#testing

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