https://www.theregister.co.uk/2018/05/21/micron_nand_enterprise_qlc/

Micron is introducing a 64-layer QLC flash 5210 ION SSD, opening a new front in the SSD-HDD marketing war.

QLC (quad-level cell) flash stores 4 bits/cell, one more than currently shipping TLC (3 bits/cell) product. The drive interface is 6Gbit/s SATA.