Grok 4.6 returns SpaceXAI to the intelligence frontier and leads on cost efficiency
Key Points
- 1SpaceXAI's Grok 4.6 has reached the intelligence frontier with an Artificial Analysis Intelligence Index score of 61, performing competitively with GPT-5.6 Sol and trailing only Anthropic’s top models.
- 2The model demonstrates exceptional agentic capabilities, particularly in multi-turn customer service and terminal-based tasks, while maintaining high efficiency in long-horizon knowledge work.
- 3By keeping headline pricing stable at $2/$6 per million tokens, Grok 4.6 offers a superior cost-to-performance ratio compared to its primary competitors, positioning it as a highly efficient option for reasoning-heavy workloads.
The paper presents an analysis of SpaceXAI’s Grok 4.6, a frontier-level large language model that achieved a score of 61 on the Artificial Analysis Intelligence Index, positioning it alongside GPT-5.6 Sol and just behind the industry-leading Claude Opus 5 (63). This release reflects a significant performance gain of 5 points over Grok 4.5 and 23 points over Grok 4.3 in just over a month.
Performance and Benchmarking
Grok 4.6 demonstrates superior agentic capabilities rather than merely static reasoning. Key benchmarks include:- GDPval-AA v2: The model achieved an Elo rating of 1753, placing it behind only Claude Opus 5 and statistically tied with Claude Fable 5 and Qwen3.8 Max.
- 𝜏³-Banking: It attained a score of 50.7%, ranking among the top two models for multi-turn customer service involving tool utilization.
- Terminal-Bench v2.1: It secured a score of 88.4%, placing it on par with current market leaders in terminal-based software engineering tasks.
- AA-Briefcase: In this private benchmark for long-horizon knowledge work, Grok 4.6 earned an Elo of 1577, reaching the Fable 5-tier. Notably, the model demonstrates high turn-efficiency, requiring approximately 53 turns and 0.5 billion input tokens to resolve tasks, compared to the ~103 turns and ~2.0 billion input tokens typically required by Claude Opus 5 (max).
Methodology and Technical Efficiency
The model maintains a 500k-token context window. While headline pricing remains constant at 6 per 1M input/output tokens, the cost of cache hits increased from 0.5 per 1M tokens.The core technical advantage of Grok 4.6 lies in its efficiency, which manifests in two ways:
- Token-Level Cost: With a cost-per-task of 5/5/$25), particularly in reasoning-heavy workloads where output token prices drive the majority of the cost.
- Architectural Efficiency: The reduction in turn count and input token consumption for complex agentic workflows indicates superior long-horizon reasoning. Because context accumulation is a bottleneck in long-horizon tasks, the model's ability to arrive at a solution using of the input tokens relative to the Claude Opus 5 (max) significantly decreases the effective total cost of ownership for high-complexity agentic deployments.