I was referring more to the NAND fabrication yield, eg: http://semimd.com/blog/2014/01/29/3d-nand-to-10-nm-and-beyond/ http://semimd.com/blog/2014/01/29/3d-nan

I was referring more to the NAND fabrication yield, eg: http://semimd.com/blog/2014/01/29/3d-nand-to-10-nm-and-beyond/ http://semimd.com/blog/2014/01/29/3d-nand-to-10-nm-and-beyon... http://www.theregister.co.uk/2015/04/09/3d_nand_gigantically_expensive_to_make/ http://www.theregister.co.uk/2015/04/09/3d_nand_gigantically... I'm making the assumption that NAND flash is binned and derated based on defects. ie, to make this drive, Samsung needs to fab 256Gbit dies. As this is on the leading-edge of their production capabilities, I'm guessing that the defect rate is not negligible, and that they accidentally make lower-capacity chips a significant portion of the time.