SK Telecom Unveils A.X K1, Korea's First 500B-Scale Hyperscale AI Model

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• USA - English

• SKT consortium conducts Korean government's 'Sovereign AI Foundation Model' project with A.X K1, positioning Korea for Global Top 3 AI Powers
• A.X K1: Korea's first 'Teacher Model' for smaller and specialized applications
• SK Telecom realizes AI as public good, advancing Korean government's 'AI for Everyone' with 20 million-user service foundation
• SKT consortium's full-stack AI ecosystem positioned to serve as national AI infrastructure

SEOUL, South Korea, Dec. 28, 2025 /PRNewswire/ -- SK Telecom (NYSE: SKM) today unveiled 'A.X K1,' Korea's first hyperscale artificial intelligence (AI) model with 519 billion (519B) parameters.

A.X K1 (519B-A33B) is poised to serve as the core foundation for Korea's ambition to become a top-three global player in the AI race, following the U.S. and China. The model marks the beginning of a full-stack AI ecosystem, encompassing all areas from semiconductors to services.

500B-Scale to Power Korea's AI Ecosystem as a 'Teacher Model'

A.X K1, Korea's first hyperscale AI model, represents a significant milestone in enhancing the global competitiveness of Korean AI within a landscape currently dominated by the U.S. and China.

Unlike knowledge-consuming AI models, A.X K1 functions as a 'Teacher Model' — a provider of knowledge — enabling knowledge transfer to smaller models, particularly those below the 70B-scale. It also serves as foundational digital social overhead capital (SOC) for the AI ecosystem. The SKT consortium will expand research to enable A.X K1 to transfer knowledge to smaller and specialized models, driving innovation for Korea.

At scales above 500 billion parameters, AI models demonstrate more stable performance in complex mathematical reasoning and multilingual understanding, according to global cases. These enhanced capabilities enable advanced tasks such as high-complexity coding and agent-based execution.

Promotes AI as Public Good, Advancing 'AI for Everyone' Through Services Already in Active Nationwide Use

The SKT consortium plans to strengthen nationwide AI accessibility by offering A.X K1 through A. (A-DoT), which has over 10 million subscribers. The consortium aims to build an 'AI for Everyone' framework, enabling the public to easily access AI via phone calls, text messages, the web and applications.

Liner, a member of the SKT consortium, operates expert knowledge search services for more than 11 million global subscribers. Expectations are high that it will provide highly accurate and reliable search services in multiple languages with A.X K1.

A.X K1 is also expected to boost industrial competitiveness through AIX — including solutions such as A. Biz for manufacturing, real-time character dialogue and autonomous behavior in Krafton's games, and humanoid AI robots.

Additionally, A.X K1 will serve as a testbed to validate the competitiveness of Korea's semiconductor industry. An AI model capable of operating at a non-standard scale of workload (500B or more) is indispensable for practically verifying memory bandwidth and inter-GPU communication speed, which are key performance bottlenecks in high-performance AI semiconductors.

Building a Full-Stack AI to Advance Korea's Global Top-Three AI Strategy

The SKT consortium's business strategy, including SK Telecom's 500B-scale AI model, aligns with Korea's national goal of becoming one of the world's top three AI nations.

In this global race, success depends not only in the performance of individual models but also on a nation's ability to scale and operate AI at a national level.

The SK Telecom-led SKT consortium includes eight organizations: SK Telecom, Krafton, 42dot, Rebellions, Liner, SelectStar, Seoul National University, and KAIST. Together, they have built a full-stack sovereign AI platform based entirely on proprietary technologies across the entire value chain, including AI semiconductors, AI data centers (AIDCs), AI models and AI services.

Building on LLM development efforts since 2018, each consortium member contributed specialized expertise: Liner enhanced accuracy through expert-level information retrieval technology; SelectStar ensured reliability through large-scale data construction and validation; Krafton provided scalability from global multimodal R&D experience; 42dot strengthened versatility through its on-device AI technology; and Rebellions improved efficiency with domestically developed NPU technology.

Already, more than 20 institutions, including major affiliates such as SK hynix, SK Innovation, SK Broadband, the Chey Institute for Advanced Studies and the Korea Foundation for Advanced Studies, have submitted letters of intent to participate. These institutions have agreed to utilize and validate A.X K1 together in real-world field settings.

The consortium plans to release A.X K1 as open-source to companies across Korea's AI ecosystem. Through major developer communities and SK Telecom platforms, the consortium will provide open-source access and APIs to foster an environment for seamless AI agent development.

Additionally, the consortium will establish an integrated support framework for AI model development and disclose portions of the training data used for model development through public and private platforms, boosting Korea's overall AI competitiveness.

"This marks a new inflection point in Korea's journey toward becoming one of the world's top three AI nations amid intensifying global competition," said Kim Tae-yoon, Head of Foundation Model Office at SK Telecom. "As Korea's leading AI company, we will continue driving our efforts to deliver AI for Everyone."

About SK Telecom

SK Telecom has been leading the growth of the mobile industry since 1984. Now, it is taking customer experience to new heights by extending beyond connectivity. By placing AI at the core of its business, SK Telecom is rapidly transforming into an AI company with a strong global presence. It is focusing on driving innovations in areas of AI Infrastructure, AI Transformation (AIX) and AI Service to deliver greater value for industry, society, and life.

For more information, please visit our LinkedIn page www.linkedin.com/company/sk-telecom.

SOURCE SK Telecom