Nvidia published some interesting new research on Friday suggesting it’s the harness, more than the underlying model, that is far more important when asking an AI to do long-horizon tasks.
The tldr: simply by using a custom harness tweaked to handled memory well and including a “supervisor” boss-like component, researchers got Claude Opus 5 to achieve a 100% score on the interactive reasoning benchmark ARC-AGI-3. (That’s a benchmark that has particularly irked rival frontier lab OpenAI.) Without the harness Opus 5 scored 30%, which was the top result among all the models tested.
