On May 23, 2025, SK hynix, the world's leading memory chip manufacturer, announced the official launch of its UFS 4.1 storage solution based on 321-layer 4D NAND flash memory technology. This breakthrough technology will not only improve the performance and energy efficiency of smartphones, but also be applied to PC solid-state drives (SSDs) and data centers later this year, further strengthening SK hynix's leading position in the field of AI storage.
1. The performance and advantages of UFS 4.1 chips
SK hynix's 321-layer 4D NAND UFS 4.1 chip has achieved significant breakthroughs in a number of key metrics. The data shows that its maximum sequential read speed is as high as 4.3GB/s, which exceeds the performance of mainstream PCIe NVMe Gen 3 SSDs (typically up to about 3.5GB/s), and although it is on par with the sequential read speed of its predecessor 238-layer products, it has significantly improved random read and write performance - random read speed by 15% and random write speed by 40%. This means that devices equipped with the chip will have a smoother experience in scenarios such as multitasking, app launching, and game loading.
In terms of energy efficiency, the new generation of chips has achieved a 7% power optimization compared to its predecessor, which is especially important for mobile devices such as smartphones, which can maintain high performance while extending battery life. In addition, the chip thickness has been reduced from 1.00mm to 0.85mm, providing more room for the design of thin and light devices.
In terms of capacity, the chip supports two specifications: 512GB and 1TB to meet users' needs for large-capacity storage. It is worth mentioning that SK hynix has emphasized that it has optimized for on-device AI, claiming that it can "ensure the stable operation of on-device AI" and provide stronger computing power support for smartphones and IoT devices equipped with AI functions, helping the development of edge computing scenarios.
Figure: SK hynix unveils 321-layer 4D NAND technology: UFS 4.1 chips will be launched in multiple fields (Source: SK Hynix)
2. Technology evolution and market layout
SK hynix will be the first to achieve mass production of 321-layer NAND flash memory in November 2024, and the release of the UFS 4.1 chip is an important milestone in the implementation of its technology. According to the plan, the smartphone memory chip using this technology will be officially launched in the first quarter of 2026, and it is expected that the first models will come from mainstream Android flagship brands.
In the PC and data center space, SK hynix plans to launch SSD products based on 321-layer 4D NAND by the end of the year. Ahn Hyun, President and Chief Development Officer of SK hynix, said, "We are strengthening our position as a full-stack AI storage provider in the NAND field by building a product portfolio with AI technology advantages. "These SSD products will not only be applied to consumer PCs, but will also enter the data center market to provide high-performance storage solutions for cloud computing, big data analysis and other scenarios. SK hynix's own brand and partners such as Kingston and ADATA are expected to launch related products.
3. Industry competition and technology outlook
At present, the NAND flash memory industry is in a critical stage of iteration to higher layers. SK hynix's 321-layer technology is already ahead of competitors such as Micron and Kioxia, which are currently mainly stuck in the 200-300 layer technology range. However, Samsung has revealed that it is developing 400-layer NAND technology, and the industry competition is still fierce.
The analysis points out that higher tiers mean higher storage density and lower unit cost, which is crucial for promoting the popularization of large-capacity storage and the development of technologies such as AI and big data. By combining the 321-layer technology with the UFS 4.1 standard, SK hynix not only continues its advantages in the field of mobile storage, but also further expands its technology moat by expanding its presence in the PC and data center markets. With the rapid development of AI and edge computing, storage products with low power consumption, high performance, and AI-optimized features will become the core competitiveness of the future market.
The launch of SK hynix's 321-layer 4D NAND technology marks a major step forward in the memory industry's direction toward higher density, lower power consumption, and stronger AI compatibility. Its diversified layout in smartphones, PCs and data centers is expected to reshape the storage market landscape in the next two years, while providing stronger infrastructure support for global digital transformation.
