Micron Technologies is finally moving into the TLC (Triple-Level Cell) NAND market, with shipments of consumer SDDs starting in Q4 this year. TLC is generally cheaper than MLC, holding up to 3 bits compared to the 2 with the older technology. This allows for cheaper SSDs as it requires fewer NAND dies to reach a certain capacity compared to MLC. By Q3 2016, Micron is expecting about 50% of their SSDs will be using TLC.
Along with Intel, Micron’s joint venture IMFT has largely focused on shrinking the process with MLC in order to gain die savings. IMFT was one of the earliest NAND producers to reach 20 and 16nm. On the other hand, SanDisk/Toshiba and Samsung have long been using TLC in their SSDs, preferring to move to new processes slower. Samsung for instance, released their first TLC drive back in 2013 and SanDisk their’s in 2014.
Combining their leading 16nm process with TLC should offer great savings for SSD buyers. TLC does come with a number of drawbacks though, most notably lower endurance and performance. TLC generally only can last 1,000 P/E (program/erase) cycles while MLC dos much better at 3,000. Even with only 1,000 cycles though, TLC should be more than enough for most consumers, especially if a bit of extra NAND is set aside. On the performance front, a caching system like those used in the Samsung 840/850 EVO or SanDisk Ultra II can mitigate most of the issues. Micron first trialed their caching system with the MX200 which should be a great starting point to work from for the TLC drives.
Micron has not yet revealed any details for their TLC drives. Intel too, given their joint IMFT venture may be trying out TLC drives in the near future. Combined with 3D XPoint and 3D NAND from SanDisk/Toshiba, 2016 should be a pretty good year for SSDs.
