The Z-NAND chips are pretty small in terms of capacity. They are also based on a Single Level Cell, in which one bit is allocated to each cell. The Z-SSD chips are basically about seven times faster than a standard SSD, as some of the industry sources say.
The creation of the Z-NAND chips and controllers will be a part of the future next-generation Z-SSD which Samsung have plan to produce. They also have plans to make partnership with Micron, which should probably happen in April next year.
The traditional HDDs are easily getting replaced by the newest SSD technology. The total value of the manufacturing of the company in the Z-SSD, is expected to reach about $30 billion by the end of 2021.