[[File:Samsung 870 QVO 8TB SATA 2,5 Zoll Internes Solid State Drive (SSD) (MZ-77Q8T0BW) 20211008 SSD023 corr.png|thumb|right|alt=A grey SSD with the text Samsung Solid State Drive"|The Samsung 870 QVO: A QLC SSD with 8 TB storage]]
Memory that stores four 4 bits per cell is commonly referred to as '''Quadquad-level Level Cellcell''' ('''QLC'''), following the convention set by '''TLC'''. Prior to its invention, QLC referred to cells that can have sixteen 16 voltage states, i.e. ones that store four 4 bits per cell.
In 2009, Toshiba and [[SanDisk]] introduced [[NAND flash]] memory chips with quad-level cells, storing [[4-bit]] bits per cell and holding a capacity of 64{{nbsp}}GbGbit.<ref name="toshiba2009"/><ref>{{cite news |title=SanDisk ships world's first memory cards with 64 gigabit X4 NAND flash |url=https://www.slashgear.com/sandisk-ships-worlds-first-memory-cards-with-64-gigabit-x4-nand-flash-1360217/ |access-date=20 June 2019 |work=SlashGear |date=13 October 2009}}</ref>
SanDisk X4 flash memory cards, introduced in 2009, was one of the first products based on NAND- memory that stores four 4 bits per cell, commonly referred to as Quad Level Cellquad-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]].<ref>[http://www.sandisk.com/about-sandisk/press-room/press-releases/2009/2009-10-13-sandisk-ships-world%E2%80%99s-first-flash-memory-cards-with-64-gigabit-x4-%284-bits-per-cell%29-nand-flash-technology/ SanDisk Ships World’s First Flash Memory Cards with 64 Gigabit X4 (4-Bits-Per-Cell) NAND Flash Technology].</ref><ref>[http://www.eetimes.com/document.asp?doc_id=1281308 NAND Flash -– The New Era of 4 bit per cell and Beyond]. EE Times. 2009-05-05.</ref>
In 2017, Toshiba introduced V-NAND memory chips with quad-level cells, which have a storage capacity of up to 768{{nbsp}}GbGbit.<ref>{{cite news |title=Toshiba Develops World's First 4-bit Per Cell QLC NAND Flash Memory |url=https://www.techpowerup.com/234729/toshiba-develops-worlds-first-4-bit-per-cell-qlc-nand-flash-memory |access-date=20 June 2019 |work=TechPowerUp |date=June 28, 2017}}</ref> In 2018, [[ADATA]], [[Intel]], [[Micron Technology|Micron]] and Samsung have launched some SSD products using QLC NAND memory.<ref>{{Cite web|url=https://www.anandtech.com/show/13606/adata-ultimate-su630-ssd-3d-qlc-for-sata|title=ADATA Reveals Ultimate SU630 SSD: 3D QLC for SATA|last=Shilov|first=Anton|website=AnandTech.com|access-date=2019-05-13}}</ref><ref>{{Cite web|url=https://www.anandtech.com/show/13078/the-intel-ssd-660p-ssd-review-qlc-nand-arrives|title=The Intel SSD 660p SSD Review: QLC NAND Arrives For Consumer SSDs|last=Tallis|first=Billy|website=www.anandtech.com|access-date=2019-05-13}}</ref><ref>{{Cite web|url=https://www.anandtech.com/show/13512/the-crucial-p1-1tb-ssd-review|title=The Crucial P1 1TB SSD Review: The Other Consumer QLC SSD|last=Tallis|first=Billy|website=www.anandtech.com|access-date=2019-05-13}}</ref><ref>{{Cite web|url=https://www.anandtech.com/show/13170/samsung-starts-mass-production-of-qlc-vnandbased-ssds|title=Samsung Starts Mass Production of QLC V-NAND-Based SSDs|last=Shilov|first=Anton|website=AnandTech.com|access-date=2019-05-13}}</ref>
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.<ref>{{cite web |url=https://www.samsung.com/semiconductor/minisite/ssd/product/consumer/870qvo/ |title=870 QVO |website=Samsung Official Site}}</ref><ref>{{cite web |url=https://news.samsung.com/global/samsung-electronics-debuts-industry-leading-8tb-consumer-ssd-the-870-qvo |title=Samsung Electronics Debuts Industry-Leading 8TB Consumer SSD, the 870 QVO |website=Samsung Newsroom}}</ref>
