The Western Digital (and Toshiba) BiCS4 technology uses a 96-layer stacking design that can be used to fabricate TLC, QLC NAND flash memory particles.
According to Western Digital's statement last year, 96-layer stacked flash memory was initially used to manufacture 3D TLC flash memory, with a single Die capacity of 256Gb (32GB). After the yield was high enough, it would shift to a higher-capacity 3D TLC and eventually make 3D QLC. Up to 1Tb (128GB).
Western Digital and Toshiba also announced last year that the single Die capacity of 768Gb (96GB) of BiCS3 64-layer stacked 3D QLC flash memory particles is likely to be available before the 96-layer QLC.
QLC flash memory can hold 4 bits of data per cell, which is one-third more than TLC. It is not only beneficial to large-capacity but also helps to reduce costs. It must be the focus of flash memory manufacturers in the future, even if its lifetime and performance continue to be large. The rate of decline.
Micron had previously shipped the first QLC-based flash-based SSD, which had a scratch life of only 1,000 cycles and was completely unsuitable for frequent writing.
