The development of a 16-gigabit 3-bit per cell (x3) NAND flash on 56-nanometer process technology by SanDisk and Toshiba offers the promise of further NAND flash memory cost reductions.
Due to higher design complexity, lower number of usable blocks and longer test times, x3 technology is expected to offer approximately 20% cost savings over comparable MLC devices at the same process generation.The key innovation of the x3 16Gb chip is the write performance of 8-megabytes per second (MB/s).
This outstanding performance is comparable to 5xnm MLC devices currently on the market and was enabled mainly through the development of an All Bit Line [ABL] architecture and advanced programming algorithms. ABL will also be deployed on all of SanDisk/Toshiba’s MLC devices boosting write performance to 34MB/s – comparable to SLC devices on the market.Alas, the full cost benefits of x3 won’t be realized for another two years, the reason being x3 is currently about one year behind MLC on the technology roadmap.
Nevertheless, Samsung and Intel - Micron Flash Technologies are expected to join the fray in 2008/9 and by 2012, 3-bit per cell NAND is forecast to account for 52.8% of NAND flash memory bits, followed by MLC NAND at 25.4%, 4-bit/cell NAND 16.6% and SLC NAND 4.4%.