SK hynix Begins Supply of 321-layer QLC NAND Up to 2TB cSSD

SK hynix, Inc. is reinforcing its leadership in the global memory market by introducing a next-gen high-performance storage solution designed for the AI PC era.The company announced on April 8 that it has begun supplying its latest cSSD, PQC21, – the 1st product featuring 321-layer QLC ⁽¹⁾ NAND flash technology.The next-gen storage solution delivers high capacity, performance, and power efficiency, meeting the rising demand for efficient storage in in AI PC environments.

At the core of the product is the combination of high-layer stacking (321 layers) and QLC technology. By leveraging the strength of QLC, which stores 4 bits per cell, the product maximizes storage capacity per unit area. The product is available in 2 capacities — 1 and 2TB — providing customers with a broader range of options.

In addition, SLC caching ⁽²⁾ technology has been applied to support fast RW performance for frequently accessed data.

Starting in April, SK hynix will begin full-scale supply of the product to Dell Technologies, with plans to continuously expand partnerships with other major global customers.

Driven by this supply momentum, the company aims to secure a leading position in storage for the next-gen AI PC market and expand its market share in QLC-based cSSDs.

“The supply of the 321-layer QLC-based cSSD marks an important milestone that demonstrates our leadership in the AI PC market,” said an SK hynix official. “We will continue to lead the high-performance NAND solution market on the strength of our overwhelming technological capabilities.”

Meanwhile, according to IDC, a global market research firm, the share of QLC NAND in the global cSSD market is expected to grow significantly from 22% in 2025 to 61% in 2027.

⁽¹⁾ QLC (Quad-Level Cell): A type of memory cell used in NAND flash that stores four bits of data in a single cell. NAND flash is categorized as single-level cell (SLC, 1 bit), multi-level cell (MLC, 2 bits), triple-level cell (TLC, 3 bits), quadruple-level cell (QLC, 4 bits), and penta-level cell (PLC, 5 bits) depending on how many data bits can be stored in one cell. As the amount of information storage increases, more data can be stored in the same volume
⁽²⁾ SLC Caching: A technology that adjusts the number of bits stored per cell in NAND flash to utilize a portion of the storage area as SLC. By first writing data quickly in SLC mode and then re-storing it in the original format, this technology enhances write performance in particular