Contributed by: David Stalcup, Chief Technical Architect on May 8, 2019.

2019 is bringing a bevy of new technologies that promise to provide greater compute performance; Intel has already released their next generation of Cascade Lake processors, AMD will be releasing their next iteration of processors, code named Rome, sometime in the 3rd quarter and Micron and Intel are gaining traction in the persistent memory category with their Apache Pass technology built on the 3D XPoint architecture. However, it is a product at the other end of the performance spectrum that really looks to have the ability to radically change the way we store data and that is Quad Level Cell nand (QLC).

The partnership of Intel/Micron has produced two interesting storage media in the past three years, persistent memory (PMEM) and now QLC. The development of Nand storage has progressed from Single Level Cell (SLC), a technology that was designed with small capacities but very high levels of endurance, to Multi-level Cell (MLC) which offered greater capacity but less endurance. Then triple level cell (TLC) technology was introduced. TLC offered even greater capacities in drive size and a more affordable acquisition cost. Announced initially by Micron, QLC offers a 33% upgrade in density over current TLC technology. The caveat with QLC is endurance, or the Program/Erase cycles available per drive typically measured in Drive Writes per Day or DWPD.

While different SSD types such as SLC, MLC and TLC offer different capacity and performance characteristics, the same applies for endurance as well. SLC drives will offer the highest levels of endurance, upwards of overwriting the drive 10-30 times per day. Progressing through the drive types, MLC DWPD numbers are approximately three drive writes per day, TLC based drives are 1 DWPD and QLC will offer approximately .3 DWPD. The low endurance rating initially looks alarming, however placement of the QLC drive is critical within the enterprise.

In a world of exploding data growth and a need to mine data for business value, a QLC based strategy could offer new potential in data retrieval and processing. LTO has gained further utility by being leveraged as a media of choice to perform data mining on long tail content. QLC makes a very compelling argument as a media with the potential to provide greater longevity and much faster access times over tape. In addition, Object Storage has been proliferating in the past several years since most data is categorized as Immortal. The ability to store large capacities of data on a media that offers low endurance rates is quite acceptable since older data is generally classified as write once, read many (WORM).

When developing your data storage strategy, it is imperative to move past the archaic idea of dollar per gigabyte. There are so many other factors to consider than just the acquisition costs. QLC offers a tremendous advantage in retrieval rates over 7200 RPM drives and LTO. Retrieval rates lead to business value and understanding that value and its impact should be part of your strategy evaluation process. New technologies such as QLC are driving an increase in storage applications that leverage tiering. Placing data in its proper location, on the proper media ensures you will derive the optimum value from your data storage strategy without fear of endurance issues from your architecture.

If your looking to overhaul your storage strategy or want to know more about QLC and other emerging options, contact us at