After Samsung, Intel and Micron, now also Western Digital and Toshiba have made an announcement related to 3D QLC NAND. The two companies today announced that they have started shipping samples of its 96-layer Quad Level Cell (QLC) NAND flash memory chips with a capacity of 1.33 Terabit per chip.Western Digital and Toshiba use the name BiCS 4 for their 96-layer QLC 3D NAND flash memory chips. The chips are produced in the joint venture flash manufacturing facility in Yokkaichi, Japan. Currently the companies ship samples to partners and the Western Digital expects to start with volume shipments later this year. Initially with Sandisk branded consumer SSDs, but later the BiCS4 QLC NAND should also end up in enterprise drives.
Toshiba is a bit behind, the company hopes to start shipping samples by September this year and hopes to start mass production of BiCS4 chips by 2019.
QLC 3D NAND stores 4 bits per cell which increases data density with one third, and allows for cheaper SSDs because fewer chips are needed for higher capacity drives. The higher density comes at a cost, SSDs with QLC 3D NAND are slower, allow for less program-erase cycles and consume more power compared to e.g the most expensive and faster Single Level Cell (SLC) NAND.