<p>➀ SK hynix has begun mass production of its 321-layer 2-terabit (Tb) quad-level cell (QLC) NAND flash memory, marking the first implementation of QLC NAND with more than 300 layers.</p><p>➁ The technology is initially set to be applied in PC SSDs, followed by expansion into data center storage.</p><p>➂ SK hynix claims the new technology doubles the capacity of existing solutions, improves performance, and enhances efficiency.</p>