Machine Heart

Jun 30, 2026 · Artificial Intelligence

Why One Extra Loop Is All a 7B Model Needs – LoopCoder‑v2’s Surprising Sweet Spot

LoopCoder‑v2, a 7B LLM, gains a massive boost on SWE‑bench Verified (43.0 → 64.4) by adding just one test‑time loop, while additional loops cause performance to collapse, a finding explained through detailed probe analysis of hidden‑state convergence, attention re‑routing, and a constant “position‑mismatch tax”.