Later this month, Toshiba will begin mass-producing NAND using a second-generation 19-nm process. According to the press release, the 64Gb (8GB) chips will be the world's smallest with two bits per cell. Each one will have a die size of 94 mm², which appears to be 17% reduction from the previous generation. The presumably gen-one 19-nm chips discussed in this Toshiba presentation (PDF) from last year have the same 64Gb capacity and a 112.8 mm² die area.
Thanks to a "unique high speed writing method," the new Toshiba NAND can program bits at up to 25MB/s. That might not sound like a lot, but the figure applies to a single chip. SSDs achieve their speedy transfer rates by addressing multiple chips in parallel, and a 256GB drive would have 32 individual dies accessible to the controller.
In addition to producing MLC chips with its updated 19-nm tech, Toshiba plans to use the process to crank out TLC NAND with three bits per cell. Mass production of that memory will begin in the firm's second fiscal quarter, which ends in September. The TLC chips will first be sold in eMMC devices meant for smartphones and tablets. They'll eventually make their way into solid-state drives targeted at PCs. Thus far, the only TLC-equipped SSD we've seen is Samsung's 840 Series.
We first spotted Toshiba's 19-nm MLC NAND in Plextor's M5P SSD last year. Since then, the flash has popped up in a refreshed version of Corsair's Neutron GTX and in Toshiba's own SSDs. It will be interesting to see how long it takes the second-gen stuff to make its way onto the market—and whether the new chips will allow drive makers to cut prices even further.