SanDisk shows off triple-bit MLC flash

February 22, 2012 // 11:26 a.m.

Tags: #flash #isscc #mlc #nand-flash #sandisk #slc #solid-state-storage #ssd

Storage specialist SanDisk is to take to the stage at the International Solid-State Circuits Conference (ISSCC) to present what it claims is the future of flash storage: a three-bits-per-cell chip capable of squeezing 128Gb into 170 square millimetres.

Like Intel and Micron's joint announcement late last year of a 128Gb flash memory chip, SanDisk is boasting of increase capacities. Where its competitor is using a 20nm process size, however, SanDisk has shrunk down even further to 19nm.

The result, the company claims, is a teeny-tiny chip which could lead to affordable terabyte solid-state storage systems in the near future. Measuring just 170 square millimetres, SanDisk claims it represents the smallest 128Gb chip yet available.

Smaller chips mean cheaper production costs and more storage in the same footprint, both of which are good news for the desktop and mobile markets alike. Although SanDisk is keeping quiet on cost at present, an analyst speaking to the Wall Street Journal on the matter predicted a drop of 20 per cent in cost-per-gigabyte for products based on the new technology.

As ever, there's a catch: a large proportion of SanDisk's presentation to the ISSCC attendees will be covering the technical complexities in implementing the new chips. Unlike traditional multi-level cell (MLC) flash memory chips, which store two bits per cell, SanDisk's implementation stores three bits per individual cell. The result is a significant increase in capacity, but one that comes at a cost of greater complexity.

Thankfully, that's something which SanDisk claims to have ironed out. When the product comes to market, it will likely be offered with a matching controller system which has already been tweaked to cope with triple-bit MLC memory.

What SanDisk isn't talking about, however, is performance. Typically, MLC memory is slower and less rugged than single-level cell (SLC) memory. With SanDisk's triple-bit MLC packing even more data into each cell, it remains to be seen what effect this has on overall data throughput from devices based on the new technology.

SanDisk has not yet indicated when it will be bringing its 19nm products to market, but it's going to have to hurry: Samsung is also presenting a flash memory chip based on a sub-20nm process size at the same event.