Old Zhang's AI Learning

Jun 15, 2026 · Artificial Intelligence

Reproducing Claude Fable 5 with Opus 4.8 and a Prompt: 90% Performance on Consumer GPUs

The article analyzes Claude Fable 5’s capabilities, dissects Anthropic’s official prompt guide, compares leaked system prompts, and demonstrates how to achieve roughly 90% of Fable 5’s performance on a consumer‑grade GPU using Opus 4.8 plus a custom prompt, while also presenting a local Gemma 4 12B coder alternative.