The AI market saw several releases in autumn 2026, including Claude Fable 5.1 on September 1 and GPT-6 Astra on September 3. Analysts emphasize that comparing models requires looking at the cost per task rather than the price per token, as token consumption varies significantly between architectures.
Artificial Analysis data as of October 3 shows Claude Opus 5.5 leading with 58 points, followed by Sonnet 5.5 at 56 points, and Fable 5.1 and GPT-6 Astra at 53 points each. GPT-6.1 Sol offers high efficiency, costing $0.72 per task with a 52-point index score.
Cost analysis reveals that Sonnet 5.5 is the most expensive at $7.67 per task due to high output token volume, while GPT-6 Luna is among the most affordable at $0.07. DeepSeek V4.1 Flash scores 39 points for $0.27, though its performance remains lower than top-tier models.
Benchmark results vary by testing environment. In Terminal-Bench 4.0, Sonnet 5.5 achieved 70.6%, while Grok 4.7 reached 37.6%. In OSWorld, Opus 5.5 leads with 81.8%. Experts note that Claude models currently excel in long agentic programming tasks, while GPT-6.1 Sol provides the best value.
Separately, Microsoft released Windows Subsystem for Linux 3.0, featuring support for Linux containers and a transition to the Linux 6.18 kernel. The source code for WSL utilities, the graphical stack, and container services is now available on GitHub under the MIT license.
