In order to achieve higher storage density, the number of stacked layers of NAND Flash is increasing, and more information can be stored in a single cell. Currently, NAND Flash chips have entered the 64-layer TLC era, looking forward to 2019, Samsung (Samsung), Toshiba and other companies will further introduce 96-layer QLC particles. In order to meet the specifications of the next-generation NAND Flash that will be mass-produced, Taiwan's two major SSD controllers, Qunlian and Huirong, have prepared corresponding solutions.
Two major Taiwanese SSD operators show QLC firepower
Group Shaolian Electronics spokesperson Yu Shaoting said that 3D NAND Flash technology continues to advance. Currently 64-layer TLC is a fairly stable product. In order to further increase storage density, NAND Flash suppliers are working hard to develop into 96-layer QLC, when a single particle The storage capacity will be up to 1TB. In fact, there are already 64-layer 3D NAND Flashs using QLC architecture, but the technical verification is very strong. It is expected that 96-layer 3D NAND Flash will not be adopted until 2019. QLC.
Zheng Yuanshun, project manager of Huirong Technology Product Planning Department, pointed out that Micron/Intel is currently the fastest growing QLC technology. There is already a small amount of 64-layer QLC NAND Flash applied to the SSD used by the server, but it is fair. Its main feature is cost performance, as far as performance can only be said to be flat. But because QLC is an inevitable development trend in the industry, next Toshiba, Samsung will also launch 64-layer NAND Flash particles based on QLC, therefore, as SSD controller Suppliers, still have to be prepared for product layout.
In response to this technology development trend, the group officially released its first control chip supporting 3D QLC during Computex. Since the QLC architecture can achieve higher storage density, the reliability and read/write speed of data storage will be Affected, the controller is equipped with the fourth-generation SmartECC technology developed by the group. Under the PCIe Gen3×4 bandwidth, the sequential read/write performance can reach 3,200MB/s, and the IOPS is 600K.
The group further explains that when the data is written into the NAND Flash, the controller supporting the SmartECC will also generate a set of correction codes and store them with the data. If the data is read back from the NAND, the control chip will pass through. The correction code corrects the data. If the error cannot be successfully corrected by the ECC correction code, the data will enter the SmartECC remediation process, and the data will be corrected by a specially designed algorithm to improve data reliability.
Not to let Qunlian specialize in the past, Hui Rong also released its next-generation PCIe SSD controller during Computex, supporting the latest 3D TLC and QLC NAND. In order to improve the reliability of data storage, its controller is unique with Huirong. Firmware technology, including end-to-end data path protection, SRAM ECC, the latest fifth-generation NANDXtend ECC technology combined with LDPC and RAID. As for read/write performance, the maximum sequential read speed of its PCIe Gen3×4 controller is up to 3,500MB/s, sequential write speed of 3,000GB / s, random read and write performance of 420K IOPS.
However, some people in the industry believe that because QLC is more reliable than TLC, even if 96-layer QLC particles enter mass production in 2019, it may take a while to apply to solid-state drives (SSD). Using 96-layer QLC The first batch of end-use products for pellets should not be solid-state drives, but applications such as USB flash drives that require less reliability.
SSD performance breaks the table
In addition to the storage capacity expected to continue to grow due to the introduction of QLC particles, the performance of SSD is also evolving. As the e-sports boom continues to burn, the performance of high-end consumer SSDs is no longer locked in the data center, the server Such as professional use of SSD, and this makes its heat has become a serious challenge that the industry must face.
The group said that the PCIe Gen3×4 SSD currently used in the data center or server, in order to ensure its stable operation, and will not slow down due to overheating, usually customers will install the cooling module on the SSD, some more sophisticated customers. In the product integration design, we will try to make the fan airflow in the server take care of the area where the SSD is located. The performance is not inferior to the high-end eSports SSD of the enterprise SSD, and it will inevitably encounter heat dissipation problems. In the SSD reference design developed for the e-sports market, heat sinks are introduced to enhance the heat dissipation capability of the SSD.
Zheng Yuanshun pointed out that the heat dissipation of high-performance SSDs is indeed a matter that must be carefully considered. In order to pursue the miniaturization of the dimensions of the modules, the industry adopts a series of M.2 specifications as the standard for SSD modules, but this specification has a large The problem is that the heat dissipation is not good. This problem is not highlighted when the speed of the particles and the interface is not fast, but with the increasing popularity of PCIe Gen3×4, this specification is not conducive to heat dissipation. Increasingly emerging.
In view of this, Huirong specifically listed low power consumption as a key design goal when developing controller chips. This is not only to save power, but also to reduce heat. Compared with the previous generation controller, the new generation controller The temperature at full speed is reduced from the original maximum of 78.6 degrees Celsius to 55.2 degrees, which helps to reduce the problem of overheating and slowdown operation of SSD products.
However, with the PCIe Gen4 standard, the interface used by future SSDs will be upgraded from PCIe Gen3 to Gen4. It is only a matter of time. Zheng Yuanshun expects that in the PCIe Gen4 era, the heatsink should become the standard equipment of SSD, because Gen4 is too fast. The heat problem will definitely be more serious than it is now, and the heat sink will become standard equipment.