Post #4
Choosing the Right Memory Solution: SLC NAND vs. e-MMC
What do applications such as printers, digital TVs, cameras, set top boxes, smart speakers and IOT devices have in common? They all require a lower density storage solution with stable and continuous support.
Many of these end applications have no need to increase storage requirements. Instead, they opt for a memory device that is well-supported in the market, has little to no technical changes planned and will be supported for many years. SLC NAND and e-MMC are the primary choices in the market for these types of end applications. The decision to use one over the other is based on the importance of their unique capabilities.
Considerations and Tradeoffs: SLC vs. e-MMC
As the end user’s density requirements increase, the option to switch from SLC to an e-MMC solution is sometimes considered. The motivation? Most of the time it is to take advantage of the lower cost per gigabyte (GB). For example, if using a 16 gigabit (Gb) SLC, why not switch to a 4GB (32Gb MLC) e-MMC at a lower cost? In this example, you are getting more memory at a lower price.
The downside is the data retention and endurance of MLC is not as good as SLC. For example, SLC NAND can support 50K W/E cycles and densities higher than 32Gb support 100K W/E cycles. In contrast, e-MMC offers 3K W/E cycles when ran in MLC mode. There is an option in e-MMC to partition the blocks to be 100% SLC. When this option is utilized, W/E cycles improve to 30K. The trade-off is the storage capacity is reduced by half so the 8GB device becomes a 4GB device when partitioned in 100% SLC mode.
The SLC Advantage
Endurance is one key advantage of SLC NAND. Another is the broad range of densities and packages offered. Densities range from 1Gb up to 256Gb, with package options including TSOP, 63BGA, 67BGA and 132BGA. Most importantly, the sustainability of SLC is unmatched. It was the trailblazer for NAND flash and continues to be important to end users and well-supported in the market.
e-MMC: A Fully Managed, Cost-Effective Solution
Now let’s review the benefits of e-MMC. Not only does e-MMC offer a lower cost per GB than SLC – it’s also a fully managed solution. This means there is a controller connected to the NAND die that manages all the nuances of NAND. This releases the host SoC of the burden of NAND flash management and makes the design process much easier.
There are numerous features and functions available within the e-MMC device that can be enabled and there is the option of partitioning blocks to meet unique system requirements. In addition, OS and important files can be stored in separate blocks and the device can be fully partitioned for better endurance. Density ranges are from 4GB through 128GB, and all have the same 11.5x13mm BGA package for easy migration to higher densities.
KIOXIA offers a wide range of both SLC NAND and e-MMC technologies to support numerous applications across consumer, industrial, communication, and emerging markets. Whether your needs prioritize high endurance with low density or a cost-effective, fully managed solution, KIOXIA has the ideal memory solution from our comprehensive product portfolio.
Notes:
Read and write speed may vary depending on various factors such as host devices, software (drivers, OS etc.), and read/write conditions.
All other company names, product names and service names may be trademarks of their respective companies.
Definition of capacity: KIOXIA Corporation defines a megabyte (MB) as 1,000,000 bytes, a gigabyte (GB) as 1,000,000,000 bytes and a terabyte (TB) as 1,000,000,000,000 bytes. A computer operating system, however, reports storage capacity using powers of 2 for the definition of 1GB = 2^30 bytes = 1,073,741,824 bytes and 1TB = 2^40 bytes = 1,099,511,627,776 bytes and therefore shows less storage capacity. Available storage capacity (including examples of various media files) will vary based on file size, formatting, settings, software and operating system, and/or pre-installed software applications, or media content. Actual formatted capacity may vary.
In every mention of a KIOXIA product: Product density is identified based on the density of memory chip(s) within the Product, not the amount of memory capacity available for data storage by the end user. Consumer-usable capacity will be less due to overhead data areas, formatting, bad blocks, and other constraints, and may also vary based on the host device and application. For details, please refer to applicable product specifications. The definition of 1KB = 2^10 bytes = 1,024 bytes. The definition of 1Gb = 2^30 bits = 1,073,741,824 bits. The definition of 1GB = 2^30 bytes = 1,073,741,824 bytes. 1Tb = 2^40 bits = 1,099,511,627,776 bits.