# Dev Update Week 9: Expanding Precompile Benchmarks & Validating Hypotheses

**Developer:** Developeruche
**Week Ending:** August 15, 2025

### Summary

This week, I concluded the benchmark analysis of `bn256` libraries in SP1 by investigating a final, crucial scenario: applying a generic `bigint` precompile to the highly-optimized `arkworks` library. The results were definitive: the precompile offered **no significant performance improvement**, confirming that high-level algorithmic optimizations in software can render low-level hardware acceleration redundant. Armed with this and previous weeks' data, I transitioned my focus to consolidating these findings into a comprehensive technical article, formalizing a data-backed proposal for a minimal precompile standard for zkVMs.

### Accomplishments This Week

* **Final Benchmark Experiment:** I implemented and benchmarked the `ark-pairing-patched` configuration, which integrated SP1's generic `mul_mod` precompile into the `arkworks`-based guest program. The test confirmed that this low-level optimization provided negligible gains on top of the already efficient library.
* **Completed End-to-End Analysis:** I finalized the complete performance dataset across all seven configurations, creating a robust foundation for drawing conclusions about precompile strategy and library choice in a zkVM context.
* **Authored Technical Blog Post:** I drafted a comprehensive technical article detailing the entire benchmark process, from methodology and the various configurations to the final results and analysis. The post highlights the key takeaways for ZK developers.
* **Formalized Precompile Design Proposal:** Using the conclusive benchmark data, I refined and formalized the "Minimal Standard" precompile proposal. The proposal now strongly advocates for a small set of high-level, protocol-specific precompiles, arguing against the inclusion of generic arithmetic precompiles that offer diminishing returns.

### Final Benchmark Results & The Law of Diminishing Returns

The final experiment with `ark-pairing-patched` solidified last week's conclusions.

| Configuration | Library | Precompile | Total Time | Key Finding |
| :--- | :--- | :--- | :--- | :--- |
| `ark-pairing` | `arkworks` | None | ~1 hr 18 min | The baseline for a highly-optimized software library. |
| `ark-pairing-patched` | `arkworks` | Generic `bigint` | **~1 hr 24 min** | **No meaningful speedup.** The overhead of the precompile call likely negated any minor gains from accelerating modular multiplication. |
| `bn-pairing-patched` | `substrate_bn` | Specialized `bn` | **~41 min 8 sec** | **🏆 Specialized precompiles remain the undisputed performance king.** |

This result provides the final piece of evidence: applying generic, low-level precompiles to an already algorithmically superior library is an ineffective optimization strategy. The performance bottleneck is not in the `mul_mod` operation itself, but in the broader cryptographic logic, which only a high-level precompile can address.

### Next Steps & Goals for Next Week

1. **Publish & Promote Findings:** I will publish the technical article on a suitable platform (e.g., a personal blog, HackMD, or a relevant community forum) and share it across technical channels to gather feedback and contribute to the public knowledge base on zkVM performance.
2. **Submit Precompile Proposal:** I will submit the formalized precompile design proposal for review by my mentor and the wider team, using the benchmark article as the primary supporting evidence.
3. **Begin Scoping Next Primitive:** As planned, I will begin the initial research and scoping for a new benchmark focused on a different cryptographic primitive, likely `Keccak256`, to test if these findings are generalizable.
4. **Code Cleanup and Documentation:** I will refactor the benchmark repository, adding detailed documentation and cleaning up the code to ensure it can be easily run and understood by others.

### Challenges & Learnings

* **Challenge: Proving the Negative:** It can be as challenging to definitively prove that an optimization *doesn't* work as it is to prove that one does. It required careful validation to ensure the precompile was being called correctly and that the results were accurate.
* **Learning 1: Know Your Bottleneck (Amdahl's Law in Practice):** This week was a masterclass in Amdahl's Law. The `arkworks` library is so efficient that modular multiplication is no longer the primary performance bottleneck. Accelerating a non-bottleneck component yields no significant overall speedup.
* **Learning 2: Precompile Call Overhead is Real:** The slight *increase* in proving time for `ark-pairing-patched` suggests that the overhead of the zkVM making a precompile call (a context switch from the guest to the host) can outweigh the benefit if the operation being accelerated is already extremely fast in software.
* **Learning 3: A Data-Driven Conclusion:** The progression of this research, from a broad survey to a highly specific benchmark, demonstrates the power of a data-driven approach. We now have a clear, evidence-backed conclusion that can confidently inform future zkVM design and developer best practices.