Artificial Analysis vs Rankscale.ai

Anthropic Launches Claude Opus 5.5 Despite Slowdown Call

Anthropic has released Claude Opus 5.5, its flagship AI model and the first in the 5.5 family, achieving the highest score ever recorded on the Artificial Analysis Intelligence Index (58) and leading six out of ten benchmarks, including outperforming OpenAI's GPT-6 Astra on Terminal-Bench 4.0. Priced 20% lower for input/output tokens and 60% lower for cache reads, it claims a 40% cost reduction for typical workloads, though higher output token usage may offset savings; it's also 30% faster and now the default in Claude Code and the Claude app. OpenAI responded by releasing GPT-6 Sol and Luna, priced ~50% lower than predecessors and offering up to 90% discounts on cached input. Both cite efficiency gains. Claude Opus 5.5 is available on Claude apps, Claude Platform, AWS, Google Cloud, and Azure, with smaller models to follow.

• Claude Opus 5.5 scores 58 on the Artificial Analysis Intelligence Index, the highest recorded, and leads six out of ten benchmarks.
• Pricing is reduced: $4 per million input tokens, $20 per million output tokens, and cache reads at $0.20 per million tokens, promising a 40% cost reduction per task (though higher output token usage may offset savings).
• Opus 5.5 is 30% faster, supports multi-agent scaling up to 100 parallel agents, and is now default in Claude Code and the Claude app.

Xiaomi MiMo-V2.6-Pro tops open weights, trained for $3M

Xiaomi released MiMo-V2.6-Pro, a natively omnimodal open-weights model with 1.02T total / 42B active parameters, trained for $3M (about 130 hours and 75B tokens). It debuts as the top open-weights model on Artificial Analysis' Intelligence Index (46) with cost efficiency at $0.435/M input and $0.87/M output tokens, under an MIT license. Xiaomi also open-sourced the RL training environment code and recipes, but not the full 7k+ task datasets, signaling an emphasis on transparency in RL training.

• Xiaomi released MiMo-V2.6-Pro and MiMo-V2.6-Flash, natively omnimodal open-weights models.
• MiMo-V2.6-Pro has 1.02T total / 42B active parameters and tops the Artificial Analysis Intelligence Index at 46.
• RL training run cost $2.6M, used 75B tokens over 130 hours.

New Articles: Benchmarking GPT-6 Astra, Intelligence Index v4.3, and more

The articles page now shows 105 articles (up from 94), with new entries including 'Benchmarking GPT-6 Astra' (Sep 9, 2026), 'Announcing the Artificial Analysis Intelligence Index v4.3' (Sep 7, 2026), 'OpenBMB releases MiniCPM5-2B' (Sep 7, 2026), 'Announcing Artificial Analysis Intelligence Index v4.2' (Sep 4, 2026), 'Muse Spark 1.3: Meta reaches the frontier' (Sep 2, 2026), 'Google has released Gemini 3.8 Flash' (Sep 2, 2026), 'Claude Fable 5.1 tops the Artificial Analysis Intelligence Index' (Sep 1, 2026), 'Agnes AI releases Agnes 2.5 Pro Beta' (Aug 27, 2026), 'Intelligence at pocket scale' (Aug 24, 2026), 'Announcing the Speech Agent Arena' (Aug 24, 2026), and 'Announcing the Artificial Analysis Search Index' (Aug 18, 2026).