Kioxia’s Efficient 3D QLC NAND Memory Enables High-Capacity SSDs

This week, Kioxia unveiled its new 3D QLC NAND devices for high-performance, high-capacity drives that could redefine what we typically expect from QLC-based SSDs. The components are 1Tb and 2Tb 3D QLC NAND chips with an interface speed of 3600 MT/s, which could enable production of 4TB M.2-2230 SSDs with decent performance.

Kioxia’s 1Tb (128MB) and 2Tb (256TB) 3D QLC NAND devices are manufactured using the company’s BICS 8 process technology and feature 238 active layers, as well as a Direct Bonded to Array (CBA) CMOS design, meaning that the CMOS (including the interface and buffer circuits) is built on a specialized node and bonded to the memory array. This manufacturing process has allowed Kioxia (and its manufacturing partner Western Digital) to achieve an especially high interface speed of 3600MT/s.

In addition to being one of the industry’s first 2TB QLC NAND devices, the component boasts 70% faster write performance than Kioxia BICS 5 3D QLC NAND devices, which is a bit of an understatement since the new chips generally have higher capacity and efficiency. This feature will be valuable for data center applications, although I don’t expect anyone to use 3D QLC memory for write-intensive applications. However, these devices will be exactly what the doctor prescribed for AI: intensive reads, content distribution, and backups.

Interestingly, the Kioxia 1Tb 3D QLC NAND, optimized for performance, boasts 30% faster sequential write performance and 15% lower read latency than the 2Tb 3D QLC component. These features (along with the 3600 MT/s interface) promise to make the Kioxia 1Tb 3D QLC competitive even with higher-end PCIe Gen5 x4 SSDs that currently use only 3D TLC memory.

The incredible storage density of Kioxia 2Tb 3D QLC NAND devices will allow customers to build high-capacity SSDs in compact form factors. For example, a 16-Hi package (measuring 11.5mm x 13.5mm x 1.5mm) can be used to build a 4TB M.2-2230 drive or a 16TB M.2-2280 drive. Even a single 16-Hi package can be enough to build a customer’s particularly fast SSD.

Kioxia is currently testing its 2TB BiCS 8 3D QLC NAND with customers such as Pure Storage.

“We have a long-standing partnership with Kioxia and are pleased to introduce their 8th generation BiCS Flash 2Tb QLC flash memory products to enhance the performance and efficiency of our all-flash storage solutions.“ said Charles Giancarlo, CEO of Pure Storage.Pure’s unified all-flash storage platform is able to meet the demanding needs of AI as well as the aggressive cost of backup storage. With Kioxia technology, Pure Storage will continue to offer unmatched performance, energy efficiency, and reliability, providing exceptional value to our customers.“

“We are pleased to send samples of our new 2 terabyte QLC drive with the new 8th generation BiCS flash technology,” said Hideshi Miyajima, CTO of Kioxia. “With industry-leading high bit density, high data throughput and excellent power efficiency, the 2TB QLC product will deliver new value for rapidly evolving AI and large storage applications that require power and space savings.“

There was no word on when the 1TB 3D QLC BiCS 8 memory will be tested or released.