GPT-6.1 Sol replaces GPT-6 Sol after just 7 days, with near-Astra intelligence

All articles September 29, 2026 GPT-6.1 Sol replaces GPT-6 Sol after just 7 days, with near-Astra intelligence GPT-6.1 Sol replaces GPT-6 Sol after just 7 days. It scores 1 point below GPT-6 Astra in the Intelligence Index at less than one quarter of the Cost per Task. Pricing matches GPT-6 Sol at $2/$10 per million input/output tokens, except that the cache read discount rises from 90% to 95%. GPT-6.1 Sol’s overall blended price for agentic workloads is therefore slightly lower than GPT-6 Sol. This represents an additional price cut, following GPT-6 Sol’s original 50% discount from GPT-5.6 Sol. Key takeaways: ➤ Achieves near-Astra Intelligence: GPT-6.1 Sol gains 4 points in the Intelligence Index vs GPT-6 Sol, and 5 points vs GPT-5.6 Sol - landing 1 point below GPT-6 Astra. It makes significant gains in agentic knowledge work, improving 4 points and 5 points in AA-Briefcase v1.1 and GDPval-AA v2.1 respectively. Other notable gains include a 12 point jump in Terminal-Bench 4.0, a 5 point jump in Humanity’s Last Exam, a 6 point jump in GDP.pdf, and an 8 point jump in AA-Omniscience Accuracy coupled with hallucination rate falling from 60% to 54%. ➤ Pushes cost efficiency frontier: At max effort, GPT-6.1 Sol costs less than a quarter of GPT-6 Astra per Intelligence Index task ($0.72 vs $3.26). It also costs 31% less per task than GPT-6 Sol ($1.05) and 64% less than GPT-5.6 Sol ($1.99). All effort levels of GPT-6.1 Sol push out the cost efficiency Pareto frontier: for a given level of intelligence, there is no cheaper model. ➤ Pushes token efficiency frontier, but uses slightly more output tokens than GPT-6 Sol: GPT-6.1 Sol uses ~10-30% more output tokens than GPT-6 Sol across effort levels. However, due to the increase in Intelligence Index score, its low and medium effort levels are Pareto optimal for token efficiency. ➤ Gains in Coding Agent Index: GPT-6.1 Sol gains 3 points on GPT-6 Sol at max effort in the Artificial Analysis Coding Agent Index, and sits 2 points below GPT-6 Astra. Coding Agent Index GPT-6.1 Sol dominates the lower-price range of the Pareto frontier for Artificial Analysis Coding Agent Index vs Cost per Task. GPT-6.1 Sol (xhigh) scores 1 point above GPT-6 Astra for less than 15% of the Cost per Task. This represents a 6 point gain from GPT-6 Sol (max). We observed the xhigh effort setting to outperform the max effort setting by 3 points. Token efficiency GPT-6.1 Sol uses 10-30% more output tokens than GPT-6 Sol across effort settings in the Intelligence Index. However, due to increases in intelligence, its low and medium effort settings are Pareto optimal for token efficiency. AA-Omniscience At max effort, GPT-6.1 Sol jumps 8 points in AA-Omniscience Accuracy coupled with a 6 point reduction in hallucination rate. AA-Briefcase GPT-6.1 Sol improves by ~80 Elo in AA-Briefcase. This is driven by increases in its rubric score and Analytical Quality Elo, while Presentation Elo falls slightly. Results by evaluation Breakdown of the individual evaluations in the Artificial Analysis Intelligence Index v4.3.2. Compare GPT-6.1 Sol with other leading models at: artificialanalysis.ai/models/releases/gpt-6-1-sol Read the latest AA-AgentPerf-Local: Benchmarking local AI agents on laptops and workstations Our open-source tool for testing how fast agentic AI runs on laptops and workstations, with launch results for the DGX Spark, Ryzen AI Halo, MacBook Pro (M5 Pro) and RTX 5090 across four open-weights models September 29, 2026 Announcing the Artificial Analysis Cyber Index Alliance The Artificial Analysis Cyber Index Alliance brings together industry partners to set a new standard for evaluating how AI models perform on enterprise cyber defense tasks. The Alliance launches alongside the Artificial Analysis Cyber Index, which combines three partner-contributed and open benchmarks to evaluate how well agents find and fix vulnerabilities. September 28, 2026 Claude Sonnet 5.5 reaches #2 on the Artificial Analysis Intelligence Index Anthropic's new Sonnet model scores 56, just 2 points behind Opus 5.5 (max), but at the highest Output Tokens per Task we have measured September 28, 2026