Seoul, South Korea – August 25, 2025 (Updated: September 23, 2025) — SK Hynix Inc. has announced that it has begun mass production of its 321-layer 2Tb QLC NAND flash product, setting a new benchmark as the industry’s first implementation of over 300 layers with QLC technology. The company completed development earlier this year and plans to launch commercial products in the first half of 2026 after customer validation.

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Breakthrough in Density and Performance

‍The new NAND die doubles the capacity to 2 terabits compared to previous solutions, and it features an increase in the number of planes from four to six. This architectural change enables greater parallel processing, which is crucial for maintaining performance in high-density storage. According to SK Hynix, the 321-layer QLC NAND delivers data transfer speeds that are twice as fast as previous QLC offerings. Write performance has improved by up to 56%, read performance by 18%, and write power efficiency has increased by more than 23%. These enhancements address historical QLC limitations and make the technology suitable for energy-sensitive environments like AI data centers.

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With the start of mass production, we have significantly strengthened our high-capacity product portfolio and secured cost competitiveness. We will make a major leap forward as a full-stack AI memory provider, in line with the explosive growth in AI demand and high-performance requirements in the data center market.

said Jeong Woopyo, Head of NAND Development at SK Hynix

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Market Rollout Strategy

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SK Hynix confirmed that PC SSDs will be the first products to incorporate the new NAND chips, with consumer devices expected in 2026. This approach allows for initial deployment in PCs before expanding to enterprise SSDs for data centers and UFS for smartphones. The company also plans to leverage its 32-die package technology to create ultra-high-capacity SSDs for AI servers, stacking up to 32 dies per package for maximum density.
The advancements are particularly targeted at the growing AI market, where low power consumption and high capacity are critical. However, despite the progress, SK Hynix notes that cheap high-capacity consumer SSDs, such as 8TB models, are not expected to arrive immediately due to high manufacturing costs and packaging complexity. This technology is more about improving efficiency and capacity for data centers rather than driving down consumer prices in the short term.

About SK Hynix

SK Hynix Inc., headquartered in Korea, is a leading global supplier of DRAM and NAND flash memory chips. The company serves a wide range of customers worldwide and is focused on advancing memory technology for AI, data centers, and consumer applications.

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