QLC comes finally

Tragedy of Samsung

Writing large stuff

Random read (worst lines)

WARNING! MICRON Plans To Introduce Octa-Level (OLC) NAND

Octa-Level Cell (OLC) NAND tech from Micron will feature 8 bits per cell for a 100% increase over QLC (per cell) and will be the first tech to essentially feature 1 byte per cell. This jump in density is something that will well exceed Moore’s Law (assuming the cell size does not increase too dramatically) and be a push for the industry and force the competition to play catch-up as well. SSD pricing for consumers will also almost certainly improve over the long term.

https://wccftech.com/exclusive-micron-octa-level-cell-tech-olc-nand-memory/

Situation on small disks - how about 14Mb/sec write speeds?

Cyan here is QLC drive write speed (first fast part is SLC caching) :-)

More QLC memory and 128 layer 3D TLC are being made

PLC coming

Fear and trembling (c)

Common 512Gb QLC SSD already has 30-50Mb/sec sustained write speed.

New ones can have 5-15Mb/sec sustained write speed, in the ballpark on late 198x HDDs.

Another Adata SU630 writing speed benchmark

yes, it is slower than USB 2,0 old flash drives.

Intel to follow Toshiba with PLC

Kioxia Corporation today announced the development of the world’s first[1] three-dimensional (3D) semicircular split-gate flash memory cell structure “Twin BiCS FLASH” using specially designed semicircular Floating Gate (FG) cells. Twin BiCS FLASH achieves superior program slope and a larger program/erase window at a much smaller cell size compared to conventional circular Charge Trap (CT) cells. These attributes make this new cell design a promising candidate to surpass four bits per cell (QLC) for significantly higher memory density and fewer stacking layers. This technology was announced at the IEEE International Electron Devices Meeting (IEDM) held in San Francisco, CA on December 11th.

3D flash memory technology has achieved high bit density with low cost per bit by increasing the number of cell stacked layers as well as by implementing multilayer stack deposition and high aspect ratio etching. In recent years, as the number of cell layers exceeds 100, managing the trade-offs among etch profile control, size uniformity and productivity is becoming increasingly challenging. To overcome this problem, Kioxia developed a new semicircular cell design by splitting the gate electrode in the conventional circular cell to reduce cell size compared to the conventional circular cell, enabling higher-density memory at a lower number of cell layers.

The circular control gate provides a larger program window with relaxed saturation problems when compared with a planar gate because of the curvature effect, where carrier injection through the tunnel dielectric is enhanced while electron leakage to the block (BLK) dielectric is lowered. In this split-gate cell design, the circular control gate is symmetrically divided into two semicircular gates to take advantage of the strong improvement in the program/erase dynamics. As shown in Fig. 1, the conductive storage layer is employed for high charge trapping efficiency in conjunction with the high-k BLK dielectrics, achieving high coupling ratio to gain program window as well as reduced electron leakage from the FG, thus relieving the saturation issue. The experimental program/erase characteristics in Fig. 2 reveal that the semicircular FG cells with the high-k-based BLK exhibit significant gains in the program slope and program/erase window over the larger-sized circular CT cells. The semicircular FG cells, having superior program/erase characteristics, are expected to attain comparably tight QLC Vt distributions at small cell size. Further, integration of low-trap Si channel makes possible more than four bits/cell, e.g., Penta-Level Cell (PLC) as shown in Fig. 3. These results confirm that semicircular FG cells are a viable option to pursue higher bit density.

Going forward, Kioxia’s research and development efforts aimed at innovation in flash memory will include continuing Twin BiCS FLASH development and seeking its practical applications. At IEDM 2019, Kioxia also announced six other papers highlighting the company’s intensive R&D activities in the area of flash memory.

New Xbox and Sony gaming consoles can be using cheapest QLC memory

And very cheap Phison E19 controller

All will be soldered on main board and very hard to repair.

Intel's memory and storage group produced Intel QLC 3D NAND solid-state drive (SSD) number 10 million based upon the QLC NAND die built in Dalian, China. Production began in late 2018, and this milestone establishes QLC (quadruple-level cell memory) as a mainstream technology for high-capacity drives.

Dream of big companies.

Note that all consumers SSDs already are being made horribly wrong without capacitors enough to finish current operation (version for datacenters and good servers always have such!).

The spread of the coronavirus pandemic has dragged down considerably shipments for most end products in the first quarter of 2020, and can lead to cut of NAND flash bit output this year to about 30%.