SK Hynix Unveils 321-Layer NAND Storage for AI Smartphones

Seoul, South Korea—SK Hynix Inc. said on Thursday it has developed a mobile storage product using 321-layer NAND flash memory technology, positioning the South Korean memory manufacturer in the market for smartphone components designed for artificial intelligence applications.

The company said its UFS 4.1 solution incorporates what it described as the world's highest 321-layer 1-terabit triple-level cell 4D NAND flash memory for mobile use.

Performance specifications released by SK Hynix show the device achieves sequential reading speeds of 4,300 megabytes per second. 

The company reported improvements of 15 percent in random read speeds and 40 percent in random write speeds compared to previous generations.

According to the company, the storage component measures 0.85 millimeters thick, down from 1 millimeter in the prior generation. 

SK Hynix said power efficiency improved 7 percent over products based on its 238-layer NAND technology.

SK Hynix plans to produce the storage solution in 512-gigabyte and 1-terabyte versions. 

The company expects to complete customer qualification by year-end and start volume shipments in the first quarter of 2026.

President and Chief Development Officer Ahn Hyun said SK Hynix plans to finish developing 321-layer 4D NAND-based solid-state drives for consumer and data center applications by 2025.

The company said the product development addresses market demand for storage components that support on-device AI while balancing computational performance with battery efficiency in mobile devices.

SK Hynix develops and manufactures memory semiconductors, including DRAM and NAND flash products.