New Fable 5 beats Opus 4.8 on real world physics simulations
We gave both models the same three prompts and asked them to build self contained HTML5 sims with real physics and no libraries:
1. Chaotic double pendulum
2. Galton board
3. Water in a spinning drum (WCSPH)
Generation cost
Fable 5: $3.35 on 68.7k tokens, time 14m 47s
Opus 4.8: $0.93 on 38.9k tokens, time 8m 10s
Fable clearly did better on the water simulation, producing a much more solid and continuous body of water. Opus left larger gaps near the walls, scattered particles around the scene, and struggled to keep the fluid stable.