Micron Increased QLC SSD Performance With Its Adaptive Write Technology

SSDs are the primary storage technology for PCs, industry applications and data centers. In data centers that means they are where data frequently accessed is stored. This is because the provide useable amounts of storage capacity and better performance than alternative technologies for the price.

The companies making SSDs have slowed in the introduction of more layers as the cost impact of added layers counts have declined. As a consequence, NAND flash companies are finding ways of increasing the cell density in the layers and particularly by increasing the number of bits stored per cell. However using higher bit per cell technology such as quad-level cells or QLC come with performance and endurance trade-offs.

Micron announced its 2600 QLC NVMe SSD for PCs and client devices recently. The product uses Micron’s 9^th-generation QLC NAND and it features the companies Adaptive Write Technology, AWT. The company improved the performance of this SSD from other QLC SSDs by using multiple bits per cell technology.

The 9^th-generation product has a 276-layers and its six-plane architecture and string stacking allows higher degrees of parallelism and increases read and write commands issued to the NAND simultaneously to improve performance. Performance is up to 3.6 GB/s. The image below shows the various sizes of this M.2 SSD.

The Micron 2600 NVMe SSD is now shipping to OEMs globally in 22x30mm, 22x42mm, and 22x80mm form factors, with capacities ranging from 512GB to 2TB. These form factors, capacity options and a single-sided design makes this product useful for handhelds, ultra-thin laptops and workstations.

SSDs built with only QLC NAND are naturally slower than SLC or TLC NAND, particularly with large file transfers. The Micron AWT uses a multi-tiered single-level cell, SLC, tri-level cell, TLC and QLC dynamic caching architecture to improve sequential write speeds. Improved write performance provides up to four times faster sequential write speeds while continuously writing up to 800GB of data to a 2TB SSD.

Micron’s tech brief on AWT says that its continuously adjusts among different NAND modes based on the volume of written data, the SSD capacity, how the SSD is used and other factors. Using the SLC optimizes for speed, TLC provides a balance between speed and capacity and QLC is optimized for maximum capacity. AWT manages traffic on the SSD by controlling which of these modes is used to enable performance benefits from SLC and TLC modes with the native capacity advantage of the QLC mode. An illustration of how this is done is shown in the figure below.

AWT seeks to store data initially on SLC and TLC cells and migrate that data to the QLC cells, freeing up the faster cells for new data. This is particularly useful in large file writes. By writing data initially on the SLC and TLC cells performance is much better than if the data were written directly to the QLC cells.

Micron says that its AWT drives are particularly good for frequent and large file transfers such as loading or reloading an operating system, transferring large files or installing large software packages. Fast SSD write speeds are also important for those who work with high-resolution video editing or other content creation tasks. Because of better performance with large file transfers, gaming and software development can also benefit from using these SSDs.

Micron uses SLC and TLC combined with QLC flash and its adaptive write technology to increase the performance of its QLC 2600 M.2 SSD.