TLC V-NAND technology to 256Gbit memory in 2015, and 512Gbit in 2017. Quad-level cell Memory that stores 4 bits per cell is commonly referred to as quad-level cell (QLC), following the convention set by TLC. Prior to its invention, the term "QLC" was synonymous with MLC in referring to cells that can have 4 voltage states, i.e. ones that store 2 bits per cell – what is now unambiguously referred to as DLC. In 2009, Toshiba and SanDisk introduced NAND flash memory chips with quad-level cells, storing 4 bits per cell and holding a capacity of 64Gbit. SanDisk X4 flash memory cards, introduced in 2009, was one of the first products based on NAND memory that stores 4 bits per cell, commonly referred to as quad-level-cell (QLC), using 16 discrete charge levels (states) in each individual transistor. The QLC chips used in these memory cards were manufactured by Toshiba, SanDisk and SK Hynix. In 2017, Toshiba introduced V-NAND memory chips with quad-level cells, which have a storage capacity of up to 768Gbit. In 2018, ADATA, Intel, Micron and Samsung have launched some SSD products using QLC NAND memory. In 2020, Samsung released a QLC SSD with storage space up to 8 TB for customers. It is the SATA SSD with the largest storage capacity for end customers as of 2020. See also Flash memory Solid-state drive StrataFlash References External links Linux Memory Technology Devices - NAND Open NAND Flash Interface Computer memory Non-volatile memory Solid-state computer storage media