Tests Show Opus 5 Faster Without Thinking but Prone to Errors

Testers including davidad found Claude Opus 5 with high effort and thinking disabled is faster but frequently makes embarrassing mistakes, while Opus 4.6 is the most temp=0-friendly and more stable Claude.

2026-08-22 ~ 2026-08-22 · 4 related posts

• Dev Tests Opus 5: Faster Without Thinking but Error-Prone — davidad · 2026-08-22
• davidad: Opus 4.6 is the most capable Claude supporting temp=0 — davidad · 2026-08-22
• Opus 5 makes high-level conceptual errors with thinking off; low temp is more stable — repligate · 2026-08-22
• Opus 5 Test: Thinking-Off Mode Faster But Prone to Hallucinations — davidad · 2026-08-22