METR: GPT-5.2 Task Horizon Estimate

Source: https://x.com (tweet) Author: METR (inferred) Date: 2025-2026

Summary

METR estimates GPT-5.2 with high reasoning effort has a 50%-time-horizon of approximately 6.6 hours on their expanded software task suite — the highest horizon estimate for any model to date. This is on their autonomy-focused evaluation.

Key Claims

  • GPT-5.2 + high reasoning: 50% task horizon ~6.6 hrs (95% CI: 3hr 20min to 17hr 30min)
  • Tested on METR’s expanded suite of software tasks
  • This is the highest recorded horizon estimate
  • METR’s methodology: measures how long a model can sustain autonomous useful work

Connection to Other Sources

Directly extends METR’s “task horizon doubling every 7 months” framework. GPT-5.2 at 6.6 hours represents a significant jump.

Concepts