GPT-5.6 vs Claude Fable 5: Which Model Wins for Physical AI?
GPT-5.6 vs. Claude Fable 5 for Physical AI, which performs best?
We tested GPT-5.6 and Claude Fable 5 on five sealed physics modeling problems to see which handles real-world engineering best. While Claude Fable 5 achieved the highest accuracy, it came at a steep cost. The GPT-5.6 variants offered faster, cheaper results but struggled with complex verification. Our analysis reveals how each model's unique work style impacts reliability in critical physical simulations.
Physical AI lives or dies on whether the modeled physics is correct.
- draginol
So Fable "won" but it cost $124.76 for marginal performance benefits over the $22.56 5.6 Sol run.
- xnorswap
A really frustrating partial presentation, given an apparent lack of testing with a spread of efforts for each model.
Given that there's no reason to believe that Fable's xhigh is comparable to GPT-sol's xhigh, or Opus xhigh, for that matter, it would be far more useful to see the effort level where these tasks no longer achieved their goals.
- hartator
It's kind of interesting this is already out of data as it's missing Kimi 3 and Opus 5.