At the A3 Technology Live conference, Micron has been sharing a word or two about its first SSDs using Quad Level Cell (QLC) NAND release. The initial SSDs will be targeted at the enterprise segment of the market and already is available this year.

Quite honestly I was expecting QLC to go mainstream straight away towards the consumer arena, as QLC offers much storage at significantly lower prices, ar, at least significantly less costly to fab NAND. QLC NAND offers 33% more capacity compared to TLC, however, does come at the cost of lower performance and reduced durability.

QLC-NAND is based upon 64-layer stacked NAND cells that can produce a capacity of 768 gigabit, allowing for 1.5 TB of storage per package. That means this type of NAND will bring high volume SSDs in vicinity, availability while remaining very cost-effective.

Basically this type of NAND thus writes 4 bits per cell. Adding more bits per cell also has an effect on the life-span of the NAND cell, and thus that brings down the number of times it can be written. Much like TLC (Triple level cell) many new technologies like error-correction mechanisms and wearing have increased the life-span of the respective SSDs. For example a 500 GB TLC based SSD can quite easily manage a 300TB written before NAND cells start to die off. TLC has roughly a 1000 PE cycles, and that is the claim for QLC as well, a 1000 PE cycles. 
  

Micron wafer with 64GB QLC flash chips

The QLC SSDs will be very interesting for read-intensive applications and long-term low-cost storage. I can see the technology end up in NAS like environments as well. Micron has not stated when the SSDs will become available but does mention that it is this year. 

SK Hynix, Toshiba, Samsung and Western Digital all previously stated to be working on QLC NAND technology.

Micron Talks Quad Level Cell (QLC) NAND memory SSDs