With the new ADATA Ultimate line of SSDs, the company pioneered a new development in the field of 3D NAND flash memory — QLC (Quad-Level Cell) technology. This made it possible to significantly reduce the cost of a gigabyte of information and at the same time increase the speed of writing and reading data, compared to products with TLC memory.
The SSD Ultimate SU630 line is aimed at installation in low-cost PCs and laptops and will be comparable in cost to conventional hard drives. Upgrading to such a media will significantly increase system performance and work with data. At the same time, the manufacturer also declares a quite acceptable durability of such disks.
What is interesting about 3D QLC technology
In the ADATA Ultimate SU630 SSD line, the manufacturer has applied a new development — 3D QLC (Quad-Level Cell) memory chips. The world got acquainted with the technology of 3D NAND multilayer flash memory in 2012 — Samsung released a drive that used chips with 24 layers of cells. Today, this figure has grown to 64, and the recording density is 3.97 Gb/mm2.
But layer density is not everything. Prior to this, information storage technology was divided into SLC (Single-level Cell) and MLC (Multi-level Cell). In the first case, a cell can store one bit of information, in the second, more than one bit.
The first technology — SLC is usually used in drives for high-level servers, because. The cost of such SSD is very high.
For home use, MLC SSDs are more suitable. In it, instead of 2 bits of information, 3 bits can be stored in a memory cell.
The TLC (Three Level Cell) memory type is a subtype of MLC memory. It has more density, but less endurance, as well as slower read and write speeds, fewer Program / Erase cycles compared to SLC and MLC.
TLC NAND type memory is used mainly in flash drives (flash drives). New technologies have made it possible to speed up cell access, and this memory has become widespread in standard SSDs.
ADATA went further and was the first to release a real product based on the new 3D QLC (Quad-Level Cell) memory. As the name implies, the manufacturer has implemented a cell with 4 levels in it, which provides for the storage of four bits of information in it. Thus, the storage density compared to TLC products is increased by 33%.
3D QLC NAND Memory Longevity
According to the manufacturer, ADATA’s Ultimate SU630 series drives last about a third less than entry-level 3D TLC NAND devices. So, the 240 GB version is designed for 50 TBW (Total Bytes Written). This is about 10 years of operation with an average recording volume of 10-15 gigabytes per day. The higher capacity models of 480 GB and 960 GB are rated at 100 and 200 TBW, respectively.
The number of electrons, that is, the level of charge, determines which bits are stored in a flash memory cell. But the more bits that must be represented, the more error prone the technology is. Today, QLC has already been implemented in real products, and the LDPC ECC algorithm protects against errors.
At the same time, for all modifications of the series, the average uptime is 1,500,000 hours. By comparison, the ADATA Ultimate SU650 with SLC memory will last 2,000,000 hours on specification. At the same time, ADATA gives a guarantee for a new budget line for 2 years.