When is local Copilot worth it? Three open-weight coders vs. Copilot out of the box

Abstract

This session compares three open-weight coding models running locally on an RTX 4090 and Apple M5 with GitHub Copilot’s default agent mode. Attendees will examine benchmark results from real repository tasks and receive a reproducible method for deciding when local inference provides practical value.

Outline

1. What Copilot BYOK changes and what it does not cover
2. Benchmark design, repository tasks, models, and hardware
3. Results across latency, tool use, and task completion
4. Workload patterns that favor local models or GitHub Copilot
5. Reproducing the comparison on your own repositories

Key takeaways

• A repeatable benchmark method for comparing local coding models with GitHub Copilot on real repositories.
• A workload decision matrix showing when local inference, Copilot out of the box, or Copilot BYOK is the better fit.
• Measured results for time to first token, tool call accuracy, and task completion across an RTX 4090, Apple M5, and GitHub Copilot.
• A clear account of which Copilot capabilities BYOK does not replace, including code completion, embeddings, and repository indexing.
• A practical method for testing the same models and metrics on your own codebase.