332 layers, 37 Gb/mm²: Kioxia and Sandisk claim the densest QLC NAND yet

Kioxia and Sandisk used the Future of Memory and Storage conference (FMS) in Santa Clara to announce their 10th-generation QLC 3D flash memory on August 4 — datelined, in full, "SANTA CLARA, Calif., Future of Memory and Storage Conference (FMS) – August 4, 2026." The joint press release claims the industry's highest bit density for QLC NAND, and for once the claim comes with its arithmetic attached.

The claims

The core sentence is compact: the "332-layer architecture and optimized floorplan design deliver up to 60% increase in bit density, achieving >37 Gb/mm² compared to the 8th-generation." Alongside density, the release says the new generation "becomes the industry's first QLC 3D flash memory technology to reach a 4.8 Gb/s interface" — a "4.8 Gb/s NAND interface enabled by Toggle DDR6.0 and the Separate Command Address (SCA) protocol." The part is built on the companies' CBA (CMOS directly Bonded to Array) technology, where the logic die is manufactured separately and bonded to the memory array, and adds Power-Isolated Low-Tapped Termination (PI-LTT) to improve I/O power efficiency.

QLC stores four bits per cell, which is how you get density records — and why the interface number matters: the four-bit tier has historically traded away performance, so pairing the density claim with a first-of-its-kind interface speed is the release's actual argument.

Mind the baseline

The 60% figure deserves a careful read: it is "up to," and the comparison is drawn against the companies' 8th-generation flash, not the 9th. That makes the number honest but flattering — a two-generation jump stated as a single delta. The >37 Gb/mm² absolute figure is the durable claim, since it does not depend on which generation you measure from.

What the release doesn't say

There are no sampling dates, no die capacities, and no product names. The closest thing to a schedule is in the Kioxia CTO's quote:

QLC technology enables the efficient storage of rapidly expanding data volumes, helping deliver greater performance and scalability for AI systems. Kioxia will accelerate development toward the commercialization of its 10th-generation flash memory products incorporating QLC technology.

Hideshi Miyajima, Chief Technology Officer, Kioxia

"Accelerate development toward the commercialization" is announcement language, not shipping language. Sandisk CTO Alper Ilkbahar frames the target market the same way, saying the generation "delivers simultaneous gains in density, bandwidth, and energy efficiency" as "AI training, inference, and hyperscale datacenter workloads drive unprecedented growth in data generation."

Why density is the whole game

Bits per square millimeter is the cost lever for flash: more bits from the same wafer area is what moves the dollars-per-terabyte curve, and QLC at this density is aimed squarely at the capacity tier — the nearline storage where hard drives still live, and where AI datasets have been piling up. If the 4.8 Gb/s interface holds up in shipping parts, it narrows QLC's traditional performance excuse at the same time. Until there are sampling dates and die specs, though, this is a process announcement: real numbers about a chip you cannot yet buy.

Primary sources: New 3D Flash Memory Technology from Kioxia and Sandisk Achieves Industry's Highest Bit Density for QLC NAND (Kioxia press release), read 2026-08-07.