What is SLC flash memory and should we care between MLC and TLC memory?

2025 UPDATE about NAND Memory Trends

In 2025, the most up-to-date industry estimates suggest that Triple-Level Cell (TLC) NAND flash memory accounts for approximately 33% of the global NAND market. This makes TLC the single-largest segment by type, according to reports from coherentmarketinsights.com. Another market analysis indicated that TLC held 58.6% of the market in 2024, showing that TLC has historically been dominant but is losing some share to other NAND types in 2025.

If TLC had around 58.6% in 2024 and is forecasted to have only 33% in 2025, this suggests that other memory types, primarily Multi-Level Cell (MLC) and Quad-Level Cell (QLC), are gaining ground. Detailed breakdowns of MLC versus SLC for 2025 are not widely available, but SLC remains a very small portion of the overall market, mainly used in specialized high-endurance or industrial applications.

The estimated mix for 2025 is approximately one-third TLC and roughly two-thirds composed of MLC and QLC combined. TLC remains the largest single technology, but the rapid adoption of QLC for high-density storage and continued use of MLC in mid-range applications is shifting the balance away from TLC dominance. SLC represents only a minor share of the total market.

Some variation in reported percentages exists because different sources measure market share differently. One report calculates TLC at 33% based on revenue, while another places TLC at 58.6% based on overall unit share in 2024. The NAND flash market is evolving rapidly, with manufacturers moving toward higher-capacity solutions, increasing the share of MLC and QLC as 3D-NAND technology matures.

In summary, TLC NAND flash is projected to hold about one-third of the market in 2025, while MLC and QLC together dominate the remaining share. SLC remains largely niche and is used where maximum endurance is critical.

Original Article – What is SLC Flash Memory Anyway?<

SLC stands for Single Layer Cell and is flash memory with a single “story” of memory and each cell has two possible states (state = a voltage level) with each state representing either a one or a zero. SLC memory has the advantage of higher write speeds because there is less time for a computer system to access the cell for a read or write function. There is also less power consumption because the amount of power to change the state is reduced since only one “story” is required to access or change the cell. SLC memory is the most expensive type of flash memory and harder to source.

A single-level cell (SLC) flash memory may have a lifetime of about 50,000 to 100,000 program/erase cycles.

Today, most consumer products are MLC flash memory or Multi Level Cell flash memory. In February 2016, a study was published that showed little difference in practice between the reliability of SLC and MLC flash memory. Because SLC memory stores less data per cell than MLC memory, it costs more per megabyte of storage to manufacture. This report and real-world experience with longevity is one reason MLC is more prevalent than SLC flash memory.

To boil it down into simple terms, picture the size of a stamp… now, that size can be used as memory and a Single Layer Cell flash memory will hold what can be stuffed into that sized stamp, but Multi Layer Cell flash memory can double that capacity yet stay at the same physical size. Or x2. The advantage to using MLC is reducing the cost of memory production, suddenly you have twice the capacity at the same price, which is a big advantage for flash drive manufacturers. It allows the company to offer larger memory storage products at cheaper prices. Of course there is a hook.

A significant portion of the flash-based memory devices on the market today are made from MLC flash and the continuing growth of flash drive products can be considered an indication that the performance is meeting consumers’ needs. However, since the use of MLC technology offers the highest density, there is a tradeoff, and you guessed it, a tradeoff of lower performance. Lower performance in the form of slower write (and potentially erase) speeds, as well as reduced write/erase cycling endurance. In addition, life expectancy of SLC flash is rated at approximately 100,000 cycles and MLC flash is rated to have approximately 10,000 cycles. That’s 10 times longer with SLC based products. However, in many cases, 10,000 erase cycles is more than sufficient for the life cycle of the product.