SanDisk has released a new line of flash memory products based on an X4 MLC chip design. The new design allows four bits to be stored per NAND cell, for a total of 64Gb (8 gigabytes) per chip.

Initially revealed in February, the 4-BPC technology is a joint venture between SanDisk and Toshiba. In the future, SanDisk plans to use the new cells to produce flash memory products with capacities exceeding 64GB

As increases in bit density shorten NAND’s lifespan, data reliability has been a major concern for 4-BPC cells. However, SanDisk CEO Sanjay Mehrotra is confident that they have overcome any potential issues with their products saying,  “Our challenge with X4 technology was to not only deliver the lower costs inherent to 4-bits-per-cell but to do so while meeting the reliability and performance requirements of industry standard cards.”

Products based on the new cells, including standard SD cards and Memory Stick PRO Duos in 8GB and 16GB flavors, have already begun shipment.