NAND flash memory demand surges, the rise of the "second-tier alliance" Kioxia and Sandisk

NAND is transitioning from a cyclical commodity to a key component of AI infrastructure, with structural changes in demand elevating prices and valuations, bringing Kioxia and SanDisk, once considered second-tier players, into the spotlight.

As AI workloads shift from training to inference, the deployment of SSDs in AI data centers is expanding, leading to a surge in data center procurement of NAND flash memory, creating market opportunities for non-traditional leading manufacturers.

Kioxia and SanDisk have maintained a deep collaboration for over 25 years, sharing the burden of expensive equipment and R&D expenses through joint ventures and co-development, thereby diluting costs through economies of scale.

In terms of technology roadmap, SanDisk focuses on integrating HBF into products from NVIDIA, AMD, and Google, while Kioxia places more emphasis on performance leaps on the SSD side.

AI Demand Creates Breakthrough Opportunities

According to EE Times, as AI workloads shift from training to inference, the deployment of SSDs in AI data centers is expanding, thus bringing new demand momentum for NAND.

For investors, this means that the prosperity of NAND is no longer solely dependent on traditional consumer electronics fluctuations, but is increasingly tied to capital expenditures and architectural evolution on the data center side.

This trend provides key opportunities for Kioxia and SanDisk. In the traditional market landscape, Samsung, SK Hynix, and Micron have long dominated. However, the rapid expansion of AI infrastructure has created a significant supply gap, prompting data center operators to actively seek a diversified supplier mix to ensure supply chain stability.

TrendForce data shows that in the third quarter of 2025, Samsung leads with 32.3%, followed by SK Hynix at 19.3%. Kioxia ranks third with 15.3%, surpassing Micron, while SanDisk holds 12.4%, with both companies increasing their influence in the global NAND landscape.

Technological Alliances Lay the Foundation

Kioxia and SanDisk have maintained a deep collaboration for over 25 years. The two companies operate NAND production bases such as Yokkaichi and Kitakami in Japan, making them one of the largest NAND flash production hubs in the world.

Technologically, they jointly developed BiCS FLASH 3D NAND, which is now at the 8th generation, BiCS8 (218 layers). According to Knowing.asia, the 10th generation product, exceeding 300 layers, is planned to begin production in 2026.

Under capital expenditure pressure, the significance of this joint model lies in cost dilution. Knowing.asia states that through joint ventures and co-development, both parties share the burden of expensive equipment and R&D expenses, leveraging economies of scale to compete against Korean storage giants.

Market Focus Diversification, Betting on Different Technology Routes

In terms of market focus, according to Knowing.asia, the market focus of Kioxia and SanDisk is clearly differentiated. Kioxia primarily supplies large electronic manufacturers in Japan and globally, while SanDisk dominates the consumer storage market and holds a strong position in the enterprise SSD sector in North America and overseas.

In terms of technology routes, HBM is limited by capacity and cost, while NAND optimizes AI architecture through two technology routes: HBF (High Bandwidth Near Storage) and AI SSD (Intelligent Preprocessing) According to Sisa Journal, SanDisk aims to integrate HBF into products from NVIDIA, AMD, and Google by the end of 2027 or early 2028. The report states that HBF uses TSV vertical stacking similar to HBM but is based on NAND, offering larger capacities at a lower cost, with a capacity approximately 10 times that of HBM, although its speed is still inferior to HBM.

Kioxia, on the other hand, is more focused on performance leaps in the SSD sector. Nikkei reported that Kioxia plans to launch a new type of hard drive by 2027 that is nearly 100 times faster than existing products, collaborating with NVIDIA for generative AI servers, with products that can connect directly to GPUs, partially replacing HBM to enhance GPU memory capacity.

Market Focus: Price Elasticity, Technology Realization, and Alliance Boundaries

Against the backdrop of rising demand for AI inference, the booming demand for NAND across the entire supply chain has become the main narrative. For the market, Kioxia's market value surpassing 10 trillion yen and SanDisk's aggressive price increase plan have strengthened expectations for NAND prosperity and profit recovery.

The next phase of variables focuses on three points: First, whether the price increase can continue and translate into profit improvement. Second, whether the technology routes of BiCS10, HBF, and ultra-high IOPS SSD can be realized on schedule. Third, how Kioxia and SanDisk can manage the boundaries of terminal competition beyond shared manufacturing and R&D to avoid synergy being offset by internal friction