The implementation of NAND Flash memory as the absolute standard storage method and replacing conventional hard drives has lasted for years, it is a transition in which different specifications compete with each other to take the lead in different markets. hardware.
The reason for this is that not all NAND Flash technologies are designed for the same type of client and solutions that may seem unsuitable for a specific use are not when we are talking about other uses. That is why it is important to take this detail into account, since the use of one type of NAND Flash or another is marked not only by cost, but also by the type of device to be used.
Capacity versus duration
NAND Flash memories have a duration depending on the type of cell that is being used to store the memory. A memory of the SLC type will use a cell to store a single bit of memory, but that implies that the cost of storage is very high. On the other hand, at the other end we have the QLC memory where up to 4 bits are stored in each cell, which means being able to build a storage device with fewer transistors, but that lasts much less time.
SLCs may seem useless to a standing user, but imagine that you have to manage a huge database, so large that it does not fit in the RAM memory and to which you continually have to make changes to its content. For this, the ideal is to use a NAND Flash SLC memory, since the wear of the cells will be less.
The memory of the TLC type onwards are those that have become popular in the domestic environment, they have an excellent balance between their price and storage capacity compared to MLCs and especially SLCs. In a home computer, changes are not usually made to the content of the hard disk or the SSD, since most programs operate in RAM and the writing changes on the hard disk are minimal.
eUFS and eMMC vs NVMe
There are two types of NAND Flash memories, the eMMC that are commonly used in PostPC devices and the NVMe that are seen in the higher caliber SSDs in the PC world. In the case of eUFS and eMMC NAND Flash memories, these are especially found in the market for PostPC devices or so-called smart devices, their particularity is that they have very low consumption since one of the things that consumes the most in a system is transfer of data. The eMMC and the eUFS have the peculiarity of not needing a flash controller, since they have it incorporated.
EMMCs have transfer speeds close to those of a SATA disk and are cheaper to manufacture than NVMe but are gradually being replaced by higher access speed eUFS. Which makes them the most popular since manufacturers can mount a low-end laptop with this type of flash memory, such as an ultrabook or a Chromebook.
NVMe memory on the other hand is much faster, and this is achieved by making use of several NAND Flash memory chips connected to what we call a flash controller. Which is responsible for managing access to the different memory chips. It is the memory used in SSDs, both in 2.5-inch format and in M.2 format.
At the capacity level, because it can use more chips, NVMe memory expires, but in recent years we have seen 3D NAND chips appear that have several hundred gigabytes of capacity, especially in high-end mobiles and tablets, however they only increase in capacity and they cannot compete with the high speed of NVMe.
The type of NAND Flash is crucial for performance
Once we have reviewed the differences between the most used types of NAND Flash it is more than clear that it will be a crucial point in the future, especially in laptops where the high energy consumption of NVMe makes them discarded in many designs that they want to keep wattage low and long battery life.
So we are going to see a separation in the different types of laptops, since the implementation of an SSD drive not only implies the fact of higher energy consumption, but also the implementation of a greater number of chips due to the need for the controller and in some cases the NVMe drive often comes with additional DRAM to increase access speed.
At the moment there are already two ranges of notebook computers, each with its ranges of processors and memory, but also with its ranges of NAND Flash memory.
NAND Flash memory in GPUs
The DirectStorage implementation allows GPUs not only to have access to their VRAM, but to go further and be able to access NAND Flash memory, which due to the level of demand in terms of bandwidth has to be of the NVMe type.
Here we enter two possibilities, the first one is that GPUs are sold with an NVMe unit incorporated inside. Which AMD already tried with more pain than glory with the graphics that you see in the image, which is a prototype that was not manufactured. If these types of cards were made then one would have to wonder if they will be made with NVMe memory and the controller soldered to the board or, failing that, with an expansion slot for an M.2 disk.
The second possibility is the fact of using the system SSD located in the PCI Express port, which is the same that happens in the new generation consoles. Here the important thing will be the number of channels that the flash controller supports, since each component of the PC that you want to access simultaneously can take a channel.
So what kind of NAND Flash beat?
Well, it depends on the application, what is clear is that the differences between the types of flash memory used come from a specific point which is the energy consumption of data transfer. Ideally, eUFS memory would be energy-efficient with the transfer speed of NVMe.
In any case, we cannot forget that the vast majority of the software on the market is still designed for the use of conventional hard drives. Programmers have to bear in mind that the transfer of data when manipulating them from the hard disk to the RAM is in a few hundred megabytes per second.
What is clear to us is the adoption of 3D NAND configurations, which is not surprising, since stacking more layers is a lower cost in many cases than using more advanced manufacturing nodes. Of course, this is a simplification, but the concept of a universal NAND Flash that works for all types of uses will have to wait and both types will evolve in parallel creating two different markets in terms of performance.