[News] WD Sets Flash Business Split Date, Unveils High-Bandwidth Flash as NAND’s Next Leap

Memory giant Western Digital has confirmed the date for the planned separation of its flash business, set to complete on February 21, 2025, according to its press release.

Western Digital currently oversees two main divisions, the hard disk drives (HDD) and flash. A previous report from Blocks and Files notes that Western Digital’s flash division includes its NAND joint venture with Japanese NAND giant Kioxia, as well as WD’s SSD production and sales.

At its investor day on February 12, WD revealed that the NAND joint venture, consisting of WD’s SanDisk and Kioxia, claims nearly one third of worldwide NAND bits produced in the third quarter, 2024.

According to TrendForce, following the spin-off, WDC’s NAND business (SanDisk) will be required to operate independently. Unlike Kioxia, which aims to ramp up production of 218-layer NAND in 2025, SanDisk remains focused on optimizing its 112-layer and 162-layer production to maximize revenue, TrendForce adds.

High-Bandwidth Flash (HBF): A Game Changer for NAND?

Notably, at the investor day, in addition to revealing new SSDs set for release later in 2025, Western Digital also announced plans for High-Bandwidth Flash (HBF), a NAND equivalent to high-bandwidth DRAM (HBM), as mentioned in the Blocks and Files report.

According to the report, SanDisk’s latest 3D NAND generation, BiCS8, features 218 layers and creates a 2Tb QLC die, claimed to be the world’s highest-capacity NAND die in production. Additionally, BiCS9, with over 300 layers, was previewed, aimed at producing a 1Tb TLC die, the report suggests.

Interestingly enough, WD’s SanDisk discloses that it is working on bandwidth-optimized NAND through its HBF concept, which could offer HBM-equivalent bandwidth with 8 to 16 times the capacity at the same cost, as per Blocks and Files.

Under this scenario, stacked HBM DRAM layers could be partially or fully replaced by NAND layers, connecting to a GPU/CPU/TPU via a logic die and interposer, according to the report.

Citing remarks from SanDisk, the report suggests that while HBF is not fully compatible with HBM, it uses a similar electrical interface with slight protocol changes. If the idea gains traction, with potential support from Micron, Samsung, or SK hynix, it could evolve into near-storage-class memory, the report adds.

Read more

• [News] WD to Spin Off NAND and SSD Business, with a Valuation Reportedly up to USD 22 Billion
• [News] Western Digital’s NAND Flash Division Head to Step Down in Early 2025 ahead of Spin-off

(Photo credit: Western Digital)