Qwen3.8-Flash-Next vs Opus 5.5: 12-Run Rust Benchmark Shows 87% vs 68% at 1/50th the Cost
deepu105 · reddit · 2026-10-21
Developer deepu105 ran a controlled six-way, twice-repeated benchmark on a real Rust feature (saving/restoring llama-server's KV cache), producing 12 public PRs scored by review questions plus CI. Opus 5.5 via Claude Code scored 87% (xhigh, $17.78, 43.5min) vs 63-69% for Qwen3.8-Flash-Next running locally on a Strix Halo laptop at Q4 quantization ($0.32-0.67, 1.1-2.1x slower). Gaps were mostly edge cases, tests, and docs; harness mattered (Claude Code passed CI 4/4 vs Pi's 1/4), and xhigh effort added little for Flash-Next. Author notes the quantized local setup isn't in Opus's league, so FP8 Flash-Next should close the gap further.
Related event: Benchmarks Show Qwen3.8-Flash-Next Near Opus 5.5 at 1/50 the Cost(3 posts)→
More from coding & agent
- Airbnb staff engineers show how they actually run AI agents in production — msharmas · 2026-10-21
- dsh-context: a visual dashboard for diagnosing agent context bloat, cache hits and token spend — aigclink · 2026-10-21
- NVIDIA expands Agent Toolkit with Knowledge Foundation, Kumo models and OpenShell runtime — NVIDIAAI · 2026-10-21
- Voice notes + AI auto-editing: a note workflow that finally stuck — Yobrogamer · 2026-10-21
- Five things healthcare teams must settle before letting an AI agent near patient data — alex_verem · 2026-10-21
- Chaperone design agent cuts token use 86%, yields 1.32 nM cortisol binder in two weeks — josephdviviano · 2026-10-21